All these patterns are free, a couple places require registration and a couple places have instruction that are a small sketchy.

http://www.savvyseams.com/bags/ this place has a few nice bags.
http://www.bellaonline.com/subjects/11193.asp Bella’s page of purse and bag pattern links.
This tote bag is the one that you pay a dollar for at grocery stores to carry your groceries. Why not make one instead? http://www.make-it-simple.com/opentot2.html
http://www.lazygirldesigns.com/ this site has a couple free patterns
Here’s a very nice shoulder bag pattern and instruction set that’s free: http://craftandfabriclinks.com/purse/free_purse_pattern.html
and here’s the main site: http://craftandfabriclinks.com/free_sewing_patterns.html
Here’s allcrafts sewing patterns page: http://www.allcrafts.net/sewing.htm and there are plenty of sewing patterns to choose from.
And finally the granddaddy of free pattern sites: http://www.freepatterns.com/ with lots of free patterns for everything.

The third one, the grocery store tote is the simplest one to make. I have it in several colours and I have made it a couple times from artist’s canvas, primed one side and painted on it with acrylic paints.