Demonology

Wikipedia, in my opinion is a unreliable source. There's many more websites with more un altered information.

Don't read Wikipedia use it to find the other sources through its references if I wasn't clear.

Go to Deliriumsrealm.com

I believe a book that may shed some insite to demonology is, "The Study of Demons and Demonolgy" by John Zaffies I believe, i believe it is a free ebook. There are also so many very good websites, mail me if you would like I'd love to help.
Best of luck,

LittleDoomWitch on Tumblr is a blog run by three demonologists from different contexts and most of their posts are answering questions.

What's the best book on demonology? Calm I get a link to the purchase page?

Demonology is the study of demons and the belief of demons. There are two types of demons i know of Lilin ,night demons and shedim demons of day. That is all i know.

One place to start is with the Lesser and Greater Key of Solomon. You can read those for free on-line athttp://www.hermetics.org/library/Library_Grimoires.html

There may not be one best book on demonology, as there are so many differing beliefs of demons and types of spirits throughout the world, even in the Western tradition.

For example, some people study the Goetic spirits in depth, and call themselves deomonlogists. They, are, after all, studying demons. The same, a person who works with entities related to a specific branch of Luciferianism might make the same claim. Neither is wrong; both are right. Demonology can be found among many traditions across the world.

I believe that 'demons' aren't all evil, and not all angels are good. There's a demon that protects me, and I've never done a pact with him, so I think he's just my guardian, or maybe my spirit guide.