1. A good firewall and antivirus
2. PeerBlock for anti-spam, anti-tracking, avoiding intentionally sent bad data (poisoning)
3. I second using uTorrent
4. Definitely get torrent files from private trackers if you can. Otherwise, some public sites like the pirate bay have comments and ratings. Read them.
5. Don't run too many torrents or connections at once or you'll waste your bandwidth with overhead. Too many connections will slow things down. You want just enough to hit your download bandwidth limit.
6. Don't max your upload speed if you're downloading. I like to leave at least 10kbps headroom so the downstream doesn't choke out. This is because every time you receive data, your computer sends a small acknowledgment.
7. SEED SEED SEED to at least twice what you download.
If you worry about who is watching your connection, you can use a proxy for your "tracker" ports but still have the data going directly between you and any peers. Flooding proxy networks with peer-to-peer data is a sin. Vidalia is a package that uses TOR (The Onion Router proxy network) and it's as easy to install as any other program. Then, set your connection preferences to use the IP address "127.0.0.1" and port 8118 for TRACKER only, not P2P. Just google vidalia utorrent tracker and you'll see images of what your settings should look like. You can also use this to proxy your browsing, but it will be slow and your ISP can still see any traffic between you and the first "hop" to the onion.
I used to have Blackcats-Games access but let it expire from only seeding. They were the best I've ever found for games and some movies and TV. Then they went completely underground and I can't get back in. Very sad. I contributed a lot of very rare stuff back in the day.