Hey there cassie!
I would assume there is some type of photo editing software that came with your camera. I have an Olympus digital camera that came with several programs, 2 of which I can use to edit the size of the image.
One suggestion... I would make copies of your photos before you start play around with them. While you may want to make them smaller for display on the web, you'll probably want to maintain the "integrity" of your originals!
As Bob said... don't hesitate to ask, we're here to help!