d-addicts. Seriously, that's all you really need. Unless you're looking for old ones that they don't have. I just google the title and "torrent" and you'll probably find some tracker that has it if it's popular enough.
to search for general torrents I use ISOhunt, mininova, and The Pirate Bay. There are other ones that people use but I find those three usually show me what I need. If that fails I use google.
About uploading, it tells you how many people are dling in the peers column, if it's 0 there are no dlers. The number in the parenthasis are the number of dlers connected to the tracker(s). If you're worried about your ratio, just keep it open and someone might pop up.
I just use the speed guide utorrent has to determine my upload cap.