"Sugar Ray Leonard", by James Haskins, 1991. although I never actually read it, it's gathering dust somewhere among other books.
It's nothing very special, but then his story isn't particularly interesting. Just an OK kid from an OK home. It's neither strong nor weak on the boxing, standard stuff really.
I wrote big article about Monzon "The violent life of Carlos Monzon", but it's in polish here's some good materials about him: Mike Casey (great writer) http://www.eastsideboxing.com/news.php?p=16712&more=1 Sports Illustrated has some good stuff to http://vault.sportsillustrated.cnn.com/vault/article/magazine/MAG1086703/1/index.htm
i know Hagler has afew bios but he hasnt released an officail one yet john garfield he means you have alot of good stories so you need to write a book