Nancy Stewart has a fantastic site where she puts up a new kids song every month. You can download the songs for free in Mp3 or Windows Media Format, and download sheet music as well. Each song is prefaced with a little explanation on how to use it and some additional activities. And if you don't want to be bothered downloading and burning CDs, or if you just want to show your appreciation, you can purchase a collection of her songs of the month on CDs, as well as several other original CDs. She's got a ton of resources on her main homepage as well.
I learned of the site in Beth's post about her Chinese New Year Lesson Plan. Thanks! I'm always shocked to find what kind of resources have been out there under my nose that I never knew about. This is one of those finds that I tell people about and they say, "What!? You didn't know about Nancy Stewart?"