picasa.google.com
The have a photo editor that works really well, and is free. It does not have all the bells and whistles that photoshop does, but for editing snap shots and playing with photos, I have found that it works really well.
Welcome to the world of DSLR cameras. My favorite part of ours is the lack of shutter lag time from when you push the button, to when it takes the photo. :)
I have used Picasa for about 3 years or so, and love it. It makes sharing the photos easy (if you want to) and makes keeping track of the photos a total breeze. :) It is installed on your computer, so other than the initial download, you can work on everything locally.
Good luck, and have fun with the camera and photos!