The strong women series by Dr. Miriam Nelson is a good place to start. She has a good explanation of why woment should lift weights, as well as a program for starting slowly. There are several books plus a website.
Strong Women These are exercises designed to be done at home, although the Extension Service in our town uses them as a basis for a seniors exercise class. ALso take a look at this article
weight lifting for "old broads" The whole website is really good
Krista Scott-Dixon - Stumptuous It also includes a series of using items found around the house! Jump in and have fun!
Start slowly and you won't get hurt.