Every digital photograph benefits from some manipulation or editing even of it’s just a little sharpening. There are various software programs that can edit photos but the most popular one is Adobe Photoshop Elements.
The best thing to do is buy a book on how to use Photoshop Elements and just work through it slowly.
Remember, the last process is always sharpening and since every print benefits from a little sharpening, it is the one area to make sure you learn properly.
Click on Adobe Photoshop Tutorials for an good place to start- its free, though does have annoying pop up ads.
Northlight Images by Keith Cooper has an excellent range of tutorials to work through.
Keep up to date with Photoshop Elements is http://www.elementsvillage.com/forums/ - a forum for exchanging ideas and learning from others.