I use mine all the time especially in the winter.Anything you can cook in an oven you can cook in a slow cooker .
You can't bake cakes in it but any every day food like stews,casseroles,soups ,joints of meat ,whole chicken.etc are fine.Even jacket potatoes.It makes the cheapest cuts of meat mouthwateringly tender.
Loads of recipes here
http://southernfood.about.com/library/crock/bl cpidx.htm
Or just Google slow cooker or crock pot ..loads of info.
There has also been lots of discussion on AB about them ....just put slow cooker in the search box.