In The New Yorker, issue dated March 16, 2009, there is a review of the current production of Our Town that has some other information in it. It is a good place to start and then read that play plus The Skin of Our Teeth, The Long Christmas Dinner and The Happy Journey/Trenton & Camden. Those are his big four plays. The last two are one-acts.
He also wrote novels and probably short stories.
You might really go into archives and read reviews of his plays in various productions.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher