ABSOLUTELY!! I wouldn't go buy the newest version, it cost quite a few pretty pennies. But head over to
Ebay and start looking around for Photoshop CS3. I found mine for $179.00! That's a steal, it normally starts in about the $500s or so. Be sure to note that there are different versions for Mac and PC, don't accidently buy the wrong one.
There is a great website called Picnik that will allow you to do editing as well, just not in the great volume that Photoshop gives. Also, go to Google and get the free Picasa 3 download. It'll automatically archive your pictures from all OVER your computer, organize them, then you can do a little editing to them and it's super easy and FREE!! I love it and use it all the time.
Also, when you find some and you want to learn, Photoshop CS3 for Dummies is a great book if you're into reading directions, if you're a visual learner (like myself) head on over to YouTube and search for 'Photoshop Tutorials'! They helped me SO much. They show you step by step how to work everything, you can pause it to take notes, etc.
Happy shooting!