The two books you linked to are both good but heavy reading. Asbridge is probably the better choice between the two.
Rather than tackle all of the Crusades, you might be better off with books that focus on one Crusade at a time. An excellent book on the Third Crusade is James Reston, Jr.'s
Warriors of God: Richard the Lionheart and Saladin in the Third Crusade.
Although not focused on the Crusades, Susan Wise Bauer's
The History of the Medieval World: From the Conversion of Constantine to the First Crusade is an excellent overview of the history that leads up to and includes the First Crusade.
Probably the best of the recent, all-encompassing books about the Crusades is Christopher Tyerman's
God's War: A New History of the Crusades. It is, I think, the single best work on the subject to date. However, it, like the 2 books you linked to, can sometimes be dense reading.