Hi Mary,

You Tuelbar has a ton of free photo resources:
Design => Free and Creative Commons Images

Here's what I do:

1. http://www.morguefile.com/ (free)

2. Then, www.istockphoto.com (pay per image)

3. www.clipart.com ($15 for a week)

All three will let you search first...1 is free, but with 2 and 3 you know you have rights to use them.