How do I change the size of a photo?

This is a complete noob question, but I'd love to put a photo of my family in my signature, but all my photos are too big and I'm not sure how to go about shrinking them down and maybe even putting border around them or something. I don't have Photoshop, only whatever comes with Windows (currently have Windows 7 if it makes any difference). If you can offer any advice I'd appreciate it.

Thanks!

I use photobucket.com to resize and edit my photos. It's really easy on there!

Thanks Jill. I was unaware that you could change edit photos on photobucket, I'll go check it out.