Bull of Heaven - Discography
http://www.bullofheaven.com/
Not necessarily an artist resource per say (unless you're looking for samples), but just a straight up recommendation for anyone who's into ambient music/psych rock. While it seems the majority of their work is electronic, they have some rock-oriented tracks, and out of the 333 tracks that are available on their website, the rock tracks are few and far between. My favorite track "Self-Traitor, I Do Bring the Spider Love" is esscentially a 90 minute improvised jazzy psych-rock jam sesh that builds and builds and builds all the way till the end. The rest of their catalogue is a pretty diverse set of soundscapes, and there are definitly gems I'm leaving out, as I just discovered this band super recently.
Anyways, I'm stickin' to three links a week for now at the minimum. Be sure to keep track, though! I have much to share in the future :^)