What is usenet?
Usenet launched in 1980 as an alternative to the BBS boards of the day. Usenet provided a distributed decentralized discussion board that could be expanded to host many users. This was counter to the common BBS boards that generally were a single server that everyone could connect to. Usenet was designed to only host text content (7-bit ascii), but some enterprising users found that if you encode a binary file into ascii you could upload it and share it with everyone. Enough history, today binary uploads on usenet dwarf simple text posting. And if you're reading this you're more interested in the binary files than the text.
How is usenet different from torrents?
Torrents work via peer to peer (p2p). Lets say we had a group of computers that all want a complete copy of a file. A couple computers have the complete file, a couple have only a piece of the file and others have none of it. Everyone in the group talks to everyone else to get the pieces they need untill everyone has a complete copy. Everyone uploads, everyone downloads. Everyone is a peer and everyone is equal.
Usenets works via a combination of peer to peer and peer to server. As far as you and other usenet users are concerned, usenet works only peer to server. You connect to a single server who sends you everything you want. There are a core group of servers that share back and fourth amongst each similarly to torrents. A user needs only to have an agreement with one of these servers to download from.

Usenet Topology, from Wikipedia
Everything on usenet servers are hosted in a category grouping structure. The category group names start with a main subject then drill down by more specific subjects each separated by periods. Examples: comp.os.linux.misc would be a group about miscellaneous Linux Operating system discussion. sci.physics.relativity would be group about scientific discussion of the physics of relativity. Almost all of the files that are now uploaded are upload to the alt.binaraies.* groups like alt.binaries.movies.hd would be hd movies.
Files uploaded to usenet are usually cut into many individual pieces called rar files. They also come with repair parts called par2 files. If you download a whole set of rar files, but one of them was bad. You can use the par2 files to repair the rar files. Sometimes this is done automatically by the software you use to download. This is covered more in-depth below.
The usenet process.
- Determine what you want to download.
- Use an indexing service to find the files on your usenet server, or browse with the usenet client software to find the files.
- Use client software to download the files from your usenet provider.
(These will be in the format of .rar and .par2 files)
- Repair and extract the files you download.
(This is sometimes done automatically by your client software)
- Enjoy your content.
Requirements to access usenet.
An agreement with a server or host. You used to be able to get free usenet access from your ISP, but in the past few years most ISPs have ditched this in favor of cost savings. Now you're going to have to pay someone for the privileged to connect to their servers.
A client program to connect to your providers servers and actually download the files.
And optionally, a service that will provide you with listings of whats currently on usenet.
Differences between usenet providers?
Every provider is going to give you "access" to usenet, but what really matters are the features they offer.
Retention: Usenet posts don't last forever and different servers keep the posts for different periods of time, mostly measured in days. These periods range from a month up to almost two years. The more popular providers offer longer periods of retention.
Speed: Each service offers a different number of connections to their server. I admit this is odd, why they don't simply offer xx MB/s of download speed I don't know. Using my current usenet provider each single connection goes 130 kb/s. So I only need 10 connections to max out my internet connections download speed. Every good provider offers 10-40 connections. So unless you have some crazy internet connection odds are any package will max your internet download speeds.
SSL: Encryption is a newer feature to usenet. Many ISPs are doing a lot of "traffic shaping". This means they take the obvious high-bandwidth applications and slow them down. For example, usenet and torrents. Using SSL to encrypt your connection means the ISP can't tell what you're sending and receiving to their servers. Meaning they may avoid throttling it down since a lot of businesses send important encrypted traffic.
As of this writing, two of the more popular usenet providers are AstraWeb and SuperNews. Each offering unlimited access for ~$10 a month post retention from 400-600 days, SSL encryption and enough connections to saturate even the best internet access. Everyone has an opinion as to which provider is better, ask around.
Choosing a usenet client.
Usenet clients actually do the connecting and downloading from your providers servers. They're the piece of software you'll be spending most of the time on. Some people swear by one program or another, but for the most part their actual functionality is very similar.
Some clients will allow you to browse usenet posts while others will only download files. Some clients will extract and repair the files you download while others will require you to use a different program for this. And lastly, some are free and some are not. Heres a list of some of the more common clients.
Windows Clients:
Grabbit: It's free, can browse usenet for posts, can post and it can repair and extract.
NewsLeecher: Costs $20, can browse for posts, can post and can repair and extract. Has a better built in search and better interface than Grabbit.
Mac Clients:
Unison: Costs $29, can browse for posts, can post and can repair and extract. This is IMO the best usenet client available under any platform and well worth the money.
Platform agnostic:
sabNZBd: Its free, works on Windows, Mac or Linux, can only download files, repair and extract. Some people swear by this, I personally prefer the other clients. sabNZBd is basically a website you set up on your local machine that handles all the downloading and extracting for you. You can even set up DNS access to have your machine download files no matter where you are.
Once you download one of these clients you'll need to enter the server settings of the usenet provider you chose earlier. This usually involves giving the program the name of the server, the address of the server, your username, your password and how many connections that server will allow you to make at one time.
Finding files to download.
If you have a usenet client that supports it, you can simply browse through the various groups and drill down till you find what you want. This is tedious, and since there aren't any specific rules about which things belong in which groups, it can be hard to find what you want. Most everyone chooses to use an index searching site.
There are two main categories of sites. Free and pay. The only difference is the pay sites usually have reviews of the files so you know you're downloading what you wanted and not malware. Recently, there's been a rash of password protected uploads on usenet. These files include links that want you to fill out a bunch of free trials on shady sites before they will give you the password. Using a pay search with file reviews can avoid these. If you get stuck with a passworded crap file, check out JimBeer's site.
Common free sites: BinSearch.info Newzleech.com NZBIndex.nl
Common pay sites: NZBMatrix.com NSBsRus.com
All these sites do is index the content on usenet, then offer you a list of these files so you can pick the ones you want. Usually you check mark the files you want and click "Create NZB". This creates a .nzb file that you download and open with your usenet client.
Whats an NZB file? Its similar to a .torrent file. An .nzb file contains a list of the files you want and the usenet groups that they're in. They're like maps for usenet.
Downloading files from usenet.
This is the easy part. Open the .nzb file you got earlier and the program should begin downloading.
Repairing and extracting downloads from usenet.
This is an area that usenet is really different from any other downloading service. Most content uploaded to usenet will be in multiple pieces. The benefit is that if any one or two pieces are broken or corrupt, it's much simplier to download or repair those small pieces rather than a single large file.
When you download something from usenet, you'll download a set of files like this:
moviename.rar.part1
moviename.rar.part2
moviename.rar.part3
and
moviename.vol01+02.par2
moviename.vol03+04.par2.
The .rar files are just your big single file cut into a bunch of little pieces. The .par2 files are repair files. Let's say you download all of those files and only moviename.rar.part2 was broken. With other services you'd have to re-download everything or try a different file, but since you have the .par2 repair files, you can fix that file so that all that downloading didn't go to waste.
Most newer usenet clients do all of this automatically for you. You'll never even have to worry about it. However, I personally like to disable the automatic repair and extract function of the usenet clients and use third party utilities. The third party utilities usually faster and offer a better view of what files are broken if I need to re-download a single .rar.part. Here's a list of various repair and/or extract software for Windows and Mac.
Windows:
QuickPar Repair with par2 files only. It's pretty much the only decent software for .par2 files on Windows. Fast and works great.
WinRAR Extract rar files only. Its the best at what it does, extracting content from .rar files. Between these two programs you should be set under Windows.
Mac:
MacPAR deLuxe Repairs with par2 and Extract from rar files. I wish it was also for Windows. Its a fantastic all-in-one solution. I have had it choke on password protected rar files before.
UnRarX Extract from rar only. Not fancy or graphical but gets the job done and supports passworded files better than MacPAR.
The Unarchiver Extract from rar files only. I've never used it before but stumbled on it while researching.
Huge Success!
That should set you well on your way to usenet. It can be daunting at first, but once you understand it, there's nothing better. I encourage people to take the time to really understand usenet. Use that client and browse through the various alt.binaries groups. There is a lot of content that none of the indexers get to. A lot of stuff hidden away. Don't forget, usenet is not one-way. You can post. Trudge over to the "Big 8" sections of usenet and discuss. If you would like a file posted, ask. Odds are someone will post it for you. I hope this helps you get started. Feel free to pass it on or post a question.
http://www.nzbsrus.com/