I'm a member of most skateboard forums around the world  , below are a list of my favourites  - not in any particular order .
each of these forums offer something different , bulldog skates is a great forum for picking up some classic gear
skull and bones skateboards has a very good forum on manufacturing decks , wheels , pressing techniques etc.
you should find most of them usefull .

www.skateboard.com.au

www.charliedontskate.com

www.direct4u.co.nz/forum/index.php          aka frontside grind

www.skullandbonesskateboards.com/forums/index.php

www.bulldogskates.com

forums.oldmanarmy.com/

Tony Hallam
www.tonyhallamskateboarding.com.au

Jamie Bartie
www.thebarties.com

Cristian Hosoi
www.hosoiskates.com

Buddy Carr
www.tailtap.com

Mike Hirsch
www.socalskateshop.com