Do you need 21 Reasons to Use Lightroom? It's a good overview of the benefits of working with digital photographs in Adobe Lightroom.

Why do you need a software system to enjoy your photographs?  Mostly because you want to have a life and keep photographing.  Trust me, you want to choose between Aperture, Lightroom and the many other options.  You want to keep up with the cataloging.  You want to enjoy your photographs.  And you want to make more photographs!

Check out 21 Reasons to Use Lightroom.