Dungeons & Dragons
You can find some information about Greyhawk world here.
Most of the books published by Hasbro can be downloaded as PDF files from a huge number of places around the world using a p2p software such as mldonkey (freeware), eDonkey (addware, spyware), or overnet (addware, spyware). The best search strings probably are "wotc" and "d&d".
Here are direct download links if you have mldonkey, edonkey or overnet installed:
WTC88165 Deities & Demigods (Indexed and Web Enhanced).pdf
WotC xxxx - D&D 3e - The Tower of Deception.pdf
WotC xxx - Caves Of Anicient Secrets 2001 (Bonus Return To The Tempel Of Elemental Evil).pdf
WotC free - D&D - Familiars.pdf
WotC 11964 - D&D - Forgotten Realms - Magic of Faerun.pdf
WotC 11850 - D&D - Manual of the Planes.pdf
WotC 11847 - D&D - Heart of Nightfang Spire.pdf
WotC 11845 - D&D - Tome and Blood.pdf
WotC 11830 - AD&D - 3rd Edition - The Speaker in Dreams.pdf
WOTC - D&D 3rd - PHB Errata.pdf
D&D 3E - Enemies and Allies.pdf
D&D - FR - WotC - Lords of Darkness.pdf
D&D - FR - WotC - Forgotten Realms Campaign Setting.pdf
D&D - FR - WotC - Faerun Map.pdf
D&D - Core Rules - WotC - Psionics Handbook.pdf
D&D - Core Rules - WotC - Player's Handbook.pdf
D&D - Core Rules - WotC - Player's Handbook [No Graphic].pdf
D&D - Core Rules - WotC - Monster Manual.pdf
D&D - Core Rules - WotC - Dungeon Master's Screen.pdf
D&D - Core Rules - WotC - Dungeon Master's Guide.pdf
D&D - Accessory - WotC - Song and Silence.pdf
D&D - Accessory - WotC - Masters of the Wild.pdf
D&D - Accessory - WotC - Defenders of the Faith.pdf
Here are boring diaries of some of the characters I played.
Campaign 8: D&D. Gary is a halfling druid
Seventh campaign: D&D. Caramip is a gnome sorcerer
Sixth campaign: D&D. Orias is a monk/druid
Fifth campaign: Dongeon. Babar is a monk elephant.
Fourth campaign: INS. Doc is a follower of Abalam, Prince of Madness.
Thrid campaign: D&D-Greyhawk. Furnok was a druid sailor.
Second campaign: D&D-BirthRight. Fraenox was druid too.
First campaign: D&D. Zimiel was mage/druid.