VideosBoard and Thinkreel were the forums where I learned all about movies and gallery submission, I started in adult thanks to them.
VP was basically dead 2 years ago already, so I see no reason why keep it up.
It became dying just when MGPs and TGPs started loosing their traffic because of tubes.
Sad.
Some others:
newbiewebmasters.com
anotheradultboard.com (or what was the name)