lol.. You use your internet browser not Azureus or uTorrent to find stuff. You just open the .torrent in Azureus or uTorrent. Use Google to search.
I did not include more sites because public sites are hit or miss. Anti filesharing companies put out fake files etc.
BitTorrent programs are always free to the best of my knowledge and BitTorrent is in most cases free, but it depends what you do with it.
If it's private sites you want then:
The Official "Open Signup Thread" - Page 176 - Zeropaid Forums Post sites open for Signup in THIS Thread - Page 1319 - FileSharing Talk
(I posted links to last page at time of posting, because open signup does noy mean open forever. So it's last page and work your way backward)