You can do both. Googling for bts will take you to bt forums for the most part. I like jazzy oddball bts so I need to look a little harder,but if you want hard rock,blues or metal bts then bt forums are the way to go.
http://wholenote.com/
WholeNote - The On-Line Guitar Community - with guitar lessons OLGA guitar tab music chords scales and other goodies...
http://www.thegearpage.net/board/
The Gear Page - powered by vBulletin
Theres two that have some fun bts if you dig for them.