At SuprNova, when you want something that isnt listed on the front page, you click the links on the front page.. I mean its right there, TV shows, Movies, Games, etc. In your case you would want to click TV shows, then on the list on the next page I believe there is a link that says Sopranos. Click that and all the files they have for The Sopranos will be listed.
With bittorrent its like any other P2P program. Your speed depends on how much other people are uploading and how many people are Seeding. Seeding is when someone has downloaded 100% of the file and are now doing nothing but uploading to other people so they can get the file. Also If you are using Shadow's or the ABC program, I would suggest you set your upload rate to about 10 KB/s while you download, and unlimited uploading when the file is done downloading. Whenever you upload at high speeds your downloading gets cut down by alot.
Another thing if you are behind a firewall you are going to have to configure it to open ports 6881-6889. These are the common ports used by bittorrent.