All I really do with BitTorrent is download TV shows I've missed. Recently, I was a late comer to LOST so I downloaded the 7 or 8 episodes I had missed. Having this luxury is at least as cool as TiVo.

However, I suspect there are some legal fine-lines being crossed or trespassed in all this, so if you get in trouble, don't look at me. You could also open yourself up to viruses, computer invasions, weapons of mass destruction, or worse. You are fiddling around with this at your own risk.

Ok, here's the 101 I gave a few friends of mine, figured I'd make it a blog post:

The way it works is that zillions of little copyright infringers out there are essentially sharing the same file in a big quid pro quo extravaganza. A bit torrent breaks a large file into oodles of tiny pieces, then through a bit torrent client you grab 1 of those pieces from one person, and another from another. Likewise, once you successfully have a piece, you'll upload that to someone else. Your client handles all this. It's one big happy party.

Here are the caveats:
1) If no one in the group has the whole file, no one can get the whole file (obviously). So sometimes you'll get a certain percent of it, and then you're hosed.

2) If there are no "seeders" to start the party, then no one can get the file. What I've seen happen on more obscure stuff is that I'll start on the file - then over night there are no seeders and I won't make any progress until a couple days later when a seeder finally reseeds the feed.

3) It won't work if no one is seeding/uploading. So.... for obscure stuff like Brimstone or Harsh Realm you might be out of luck There are some IRC channels where you can request folks start a seed and with some work I suspect you'll get success, but this is a serious limitation for getting old good stuff.

4) It's  SLOW unless you have things configured right, which can be tricky. Even on fat pipe it can take a good day to download a show (although you can get 2-3 going at once). A typical show is 350MB and a typical download speed is somewhere between 6K-160K. So it takes a while even on good seeded and high peer-count torrents.

I've barely scratched the surface. There's a whole nerdy underground dealing with this that can get you further once you get into it.

Here's the client I use.
http://pingpong-abc.sourceforge.net/
Azereus - this client rocks! It's chock full of great nerdy widgets, reports, visuals and statistics, plus after trying several, it's the best at getting along with my NAT (i.e. firewall/router). Plus it's the fastest client I've seen. Most bittorrent users use this client. It is user friendly and even though I had to break my religion and install the Java JRE, I haven't had any problems with it. It's awesome.

Another thing you must do to get good performance, is punch a hole in your firewall for the  ports (6881-6999). What happens is that if others with the same torrent can connect to you without you connecting first to them, you'll have more connections, and things will move much faster than if they can't. When they can't connect to you without you first connecting to them, you only get data from a few and the speed of your download will be quite a bit less. With Azereus you'll get a green smiley face once everything is properly setup and you'll notice a huge increase in performance.

Here are a couple good TV show sites I've found. No porn and have the current stuff right away.

digitaldistractions
bi-torrent
btefnet (*sniff* they got sued and are now gone, they used to be the best source for the newest shows.)

Best torrent search site: TorrentTyphoon.
These guys are doing it right!

If anyone has any other tips, add them to the comments.

Good luck!