I use Pixlr to create my buttons. It's intuitive, easy to use, and free. For backgrounds, I've had a lot of luck with texturemate. They have a ton of different textures from wood and steel to dirt and fabric. And, it's free! For pictures, but sure you aren't stealing. Googling something and copying the picture is not okay. Those graphics, pictures, etc. were created by someone and you need their permission to use them. If you're looking for something safe to use (and free, do you sense a theme), I love Wikimedia. It's well organized and every picture has very clear guidelines and how it can and cannot be used.
If, like me, you need a little hand holding, here is a great tutorial from Carrie Butler on how to use Pixlr to make your button.
In unrelated news, today is my birthday. I'm still not 40, so it's okay to celebrate.