Comment Great book for web apps (Score 0) 338
Steve Krug's "Don't Make Me Think" is an excellent book for web usability. Many of the principles in the book apply to good app design as well.
http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1199369216&sr=8-1
http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1199369216&sr=8-1