7 links
Classification of Demons By Month
en.wikipedia.org
Certain demons were believed to have more power depending on the month.
Demonology - A Comprehensive Guide
djmcadam.com
A comprehensive discussion of demons and demonology from various ancient text sources.
Geifodd's Demonolatry
geocities.com
Personal site with some articles, poetry, and a ritual. Includes information about Azazel, Lilith, and some ancient Middle Eastern gods such as Set, Anpu, and Ishtar.
Stella Tenebrarum - Demonolatry
geocities.com
Short but informative article on this hard to find subject area.
Wikipedia: List of Specific Demons and Types of Demons
en.wikipedia.org
Large list of demons from various cultures and mythology.