A couple of titles to consider:

The Second Sexism by David Benatar

Benatar makes a compelling case for the existence of sexism against men and the need for a social movement to address it. The book is fairly dry and academic, and Benatar doesn't spend much time dissecting the issues or proposing solutions, but he does an excellent job of outlining the reasons for the MRM's existence.

The War Against Boys by Christina Hoff Sommers.

Sommers argues that changes to America's education system have led to a generation of boys with educational and social problems. Her evidence is a bit sparse in places, but she is a compelling author.

The Myth of Male Power by Warren Farrell.

This is probably the most influential book in the MRA library. Farrell meticulously deconstructs the male gender role and paints a picture of men as vulnerable, confined, and disposable.