I found a much better way (IMO) than the dodge tool yesterday whilest reading a PS book in the bookstore. They point out that the dodge tool "damages" the pixels and you cannot get them back to their original state (other than undoing history, of course).
Here's what I learned... and it has made a really big difference for me so far!
1) Create a new layer via the top toolbar (not the little icon) Layer->New->Layer.
2) In the dialogue box that pops up, change the Mode to Overlay, then it allows you to check the little checkbox that says "Fill with Overlay-neutral color (50% gray)". Check this box! That's the magic.
3) Pick your paint brush or whatever you want to use and lower the opacity to 10-15%, whatever you discover you like.
4) Now just paint white where you want to lighten something, and black where you want to darken it.
Change your mind later, just delete the layer and voila... back to where you started.
Also, I've noticed with the burn tool, if you click to paint and hold the button down, going over the area twice with one brush stroke will dodge it twice as light. Whereas with this method, you don't have to be careful not to overlap you painting because it will not keep incrementing your paint stroke... like that makes any sense... how can I say this. If you paint with 10% opacity and click and paint over and over the area without letting go of the mouse button, you only paint 10%. Whereas with dodge if you make a stroke and go back over it again, you dodge essentially 20%. But with this new method, you can still paint over the area as many times as you want to build the lightness.... paint it again at 10% and you have an effective 20% lightening.
Hope some of that made sense... but I find it works great! Hope this was able to finally help someone out here, as I have been helped greatly by many on this board.
I felt the same way after trying it out!

