Robert Spencer quotes one of the great insightful thinkers of his day on Islam (pg. 25).
Spencer's PIG on Islam and the Crusades places some information in graphical asides, aka boxes.
The Battle of Badr section (pp. 7-10) is an important read for any student in military history.
All the early conquests described in Spencer's PIG to Islam should be studied carefully.
The Grim Milestone of Blogs "I find the language and rhetoric coming from America too confrontational" - Prince Charles "Nuts" - Gen McAuliffe America: Saving idiots from themselves since WWI