It seems when men first come to feminism, they begin a series of laments about the absolute lack of information about guys, about how no one notices how they suffer. This goes on for an indeterminate period of time, and the guy either A) decides feminism is "wrong" for "excluding" him and he becomes an MRA or B) he opens his eyes and realizes there are already more books and blogs about men than he can read. I took route B, after quite an overdose of complaining.
After having been a feminist for a while, I started being interested in men and masculinity and how they related to feminist theory and action, and I, too, found myself a bit frustrated at the lack of interesting theory of masculinity. But then, slowly, one recognizes that there plenty of theory to get started with.
Update: Michael Flood of xyonline notes in the comments that he has created a fairly comprehensive reading list for matters of men and masculinity, indexed in various ways. This list is very welcome, thanks Michael.