Evolution's Rainbow: Diversity, Gender, and Sexuality in Nature and People is a must read for anyone remotely interested in this topic.
One of the reasons I say 'must read' though is that Roughgarden's idea have been quite controversial.
If you don't have the time to read a whole book then there are numerous essays and magazine articles that summarize the book and its arguments eg. The effeminate sheep and other problems with Darwinian sexual selection.
Take a look, it might inspire you to read the book.