For Men Only by Shaunti and Jeff Feldhahn is short easy to read book packed full of good insight for men in relating to their wives.  Bang for the buck this is one of the best books written for men.  Much of the information is based on surveys done on women so it is hard to argue the findings that serve as the basis for this book.

I might also mention that it is a part of an excellent series all following the same format.  I read For Women Only to get some insight on the other side of things.  I found that it was right on target.  Also, For Parents Only is a great resource for parenting teens.