Stacy wrote a great post explaining different ways to fix imperfections in your pictures using Photoshop. I don't think children need a lot of retouching, if any at all, but there are times I'd like to use it to remove a scratch or maybe crumbs leftover from a yummy meal.
I'm still learning how to use all the tools she talks about so the tips she gives are really helpful. Check out her archives too for more great tutorials. I've also got a growing list of tips on the sidebar too!