The Krigsspll.dk site offers a very large selection of downloadable flags for the Crusades. They are all very well done.
crusades
Crusader Banners
The Fanaticus Site has a set of Crusader banners for you to download and print. They’re in 15mm scale.
List of Arabic Names
For colonial games fans, here’s a gamers’ list of Arabic names.
Ironbow rules
From The Perfect Captain, Ironbow is one of their series of beautifully illustrated wargames where the graphics are not just eyecandy, but integrated into the rules and play of the game. Truly innovative stuff. Ironbow covers the crusades era from 1096 to 1192.
Early Crusader Period Flags
Here’s a selection of early crusader period flags.