wiki says....
"The Moon Is a Harsh Mistress is a 1966 science fiction novel by American writer Robert A. Heinlein, about a lunar penal colony's revolt against rule from Earth. Originally serialised in Worlds of If (December 1965, January, February, March, April 1966), it received the Hugo Award for best science fiction novel."
I've had this one on my "to read" shelf for a while too. I've been told that it's a Sci-Fi classic. I've even been told that when it comes to novels it's THE sci-fi classic.