Honestly I am new to it all in general, but I have done some research on them in the past. talkgold.com is a good site where lots of investors keep spreadsheets of ROI%, etc..
This site actually has a good rep. Its got a 42 page thread right now since the beginning of feb.
http://www.talkgold.com/forum/showthread.php?t=483486&page=42