Useful information, bits and scraps of data, and everything that might come in handy goes here.

Play Aids:
Map of the House - For The Spirits' Revenge
1925 Calender - Extremely useful when running the Masks of Nyarlathotep campaign where every day counts
Clippings About the Carlyle Expedition - Play aid for Masks of Nyarlathotep
Information about Jackson Elias - Play aid for Masks of Nyarlathotep
A Letter from Miriam Atwright - Play aid for Masks of Nyarlathotep
Jackson Elias's Notes - Play aid for Masks of Nyarlathotep
Dr. Hudson's Notes - Play aid for Masks of Nyarlathotep
Newspaper Clipping on Raid - The players learn that the police are not equipped to deal with certain things

Artifacts:
The Book of Veils - An evil book to confound your players with
The Head of Baphamut - The Templar's asked questions of it and the head answered.  The players ask...

Scenarios:
The Spirits' Revenge - A Mythos light introductory scenario.  Perfect for helping new characters and players get to know each other
The New Templars - Another Mythos light introduction to the game (though in this case my players hit the bad stuff quickly)

Useful Information:
A Brief History of Spiritualism - Some brief notes on spiritualism I passed around after running The Spirit's Revenge.  You might find it useful before running the scenario.
Joel's Recommended Lovecraft Reading List - Don't know the works of the good Mr. Lovecraft?  Here's a few to get you started.
Joel's Solution of Cthulhu Party Cohesion - So, how do you stick all these people together?