Here are some "BEFORE" and "AFTER" processing examples using Lightroom on some of my pictures. Click to enlarge, to see the full effects.
BEFORE increasing sharpness (left) and after increasing sharpness (right). It made more of a difference than I would have thought.
BEFORE increasing sharpness and without additional vignette (left) and AFTER increasing sharpness and adding additional vignette (right). Made a big difference in this salamander altercation capture.
BEFORE spot removal (left) and AFTER spot removal (right). I hadn't cleaned my lens in a while, and didn't notice these specks of dirt on the lens until after I had already taken this picture. I thought that it would take a large amount of work to remove these dirt spots, but thanks to Lightroom, it took only a few seconds. Pretty awesome what some of these programs can do without consuming a lot of time.