Most occultists are pretty good at finding what they need (which I suppose makes sense when you figure occult basically just means hidden). If you’re a student of the occult you probably already know about these resources. But just in case you don’t, here are four of my favorites:
The Online Books collection at University of Pennsylvania. There are links to full scans of over 40,000 books on a variety of subjects. For example, check out the selection of links on the subject of Demonology.
The University of California Digital Library. Over 4 million books. Ready the paddles; your heart may skip a beat.
The Internet Sacred Text Archive. It is what it says it is. Dig it.
Cimmay.com. It’s stated purpose is to introduce the world to the Urantia Papers, but there are a ton of cool old books on other subjects. Check out The Angels and their Ministrations by Robert M. Patterson. Nice.