After Saladin's great victory at the Battle of Hattin in 1137, Outremer, as medieval westerners called the remaining Latin or Catholic enclaves in the Mediterranean, were no longer a threat to Islam.  Its military elites preferred to live in peace, focusing on trade as much as on the defense of Christendom's holy places.

A comprehensive and fairly objective historical essay on the Outremer can be found at the Freisian School.  There is a chronicle of the Fall of Jerusalem (which closely followed Hattin) by Roger of Hovedon at the fabulous Medieval Sourcebook.

And for an informative, entertaining and occasionally riveting book that will send you running to Google to re-read accounts of battles you thought you knew, check out Amin Maalouf's The Crusades Through Arab Eyes. I really can not recommend this book enough - especially for his myth-busting account of the fall of the Outremer city Acre and the conduct of Richard the Loinheart (Chapter 11 - "The Impossible Encounter").