A List of Dungeons & Dragons Deities

Wikipedia is a great place to learn about virtually anything. Included in the link above is a list of all popular and several rather unknown deities.

"This is a list of deities of Dungeons & Dragons, including all of the current gods and powers of the "Core Setting" for the Dungeons & Dragons roleplaying game. Because the Core Setting is based on the World of Greyhawk, the Greyhawk gods list contains most of the deities listed here, and many more." (Wikipedia)