This will be, primarily, a list of bands I like, a list of sites for music, whether theory, forums or otherwise.

Bands:
Anathema
Devin Townsend
Dream Theater
Pain of Salvation

Forums
Gearslutz – Hi to low end recording forum
Aussie Guitar Gear Heads
Northern Sounds – Primarily a sample based discussion forum
John Petrucci Forums
Soundsonlie Forums – Forums for Sounds Online

Education
Art and Science of Sound – A look at audio recording, 3 DVD’s, a project created by Alan Parson
Sound on Sound magazine – A magazine covering many aspects of audio. I particularly recommend the Studio SOS section for home studio enthusiasts