The ProSoundWeb Forums This is a professional audio comunity forum, there is much knowledge that can be gained by reading the posts on this site. High lights include Havey Gerst's forum on low budget solutions, and Mixerman's forum on well... its Mixerman need I say more?
The Forums at Harmony-Central Lots of great recording stuff here. Its the home of Craig Anderton's Sound, Studio and Stage forum.
Home Recording dot com BBS Great recording forums including the always interesting MP3 Mixing Clinic and Studio Building and Display Forums
John Sayer's Recording Studio Design Forum Learn about studio design and construction from one of the masters.
The Forums of Recording.org A good resource of general recording information.
The Recording Project ForumsA unique collection of forums slanted towards the recording musician.
Studio Recording Engineer Forums Although not a popular as some of the other forums, this is a very good resource of knowledge
SAE refernece material center Some excellent informaiton on recording techniques can be found here. Some great links too!
Inside Home Recording (IHR). An excellent Podcast geared towards the home recordist and musician. Always informative and entertaining.
Project Studio Network. Another great Podcast resource for those of us on limited budgets!