Diogenes the Cynic: Sayings and Anecdotes, with Other Popular Moralists by Oxford World's Classics isn't a bad source, but like Leon_Grotsky said, you're inevitably going to come away disappointed (like I did) because we don't really have any of his original writings.

Along with Antisthenes and Crates of Thebes, Diogenes is considered one of the founders of Cynicism. The ideas of Diogenes, like those of most other Cynics, must be arrived at indirectly. No writings of Diogenes survive even though he is reported to have authored over ten books, a volume of letters and seven tragedies. Cynic ideas are inseparable from Cynic practice; therefore what we know about Diogenes is contained in anecdotes concerning his life and sayings attributed to him in a number of scattered classical sources.

I think you are better off looking or literature on Cynicism/Kynicism.

The only thing known about his life as far as I know is a passage in the Lives of Eminent Philosophers by another Diogenes, it's about 10 pages and should easily be found on the internet.

For example: http://www.gutenberg.org/ebooks/57342

It's book 6 chapter 2.