Hmm, I didn't keep a psd of the pic, but I'll try and recall what I did to the best of my ability.
I started out with duplicated the layer twice. At this point I had 3 layers - the original, one I would use for skin toning, and one I would use for initial lighting. I set the second layer in the stack to screen. This drastically improved the lighting of the image. The top layer I used the quick selection tool to quickly select all of the skin. Then I used the "refine edge" wizard to blast up the feather radius so that any changes I made would blend from the skin to other parts of the picture smoothly, I created a new layer via copy with this selection and applied a gausian blur of something around 5 I believe.
This gave me a good base to work with.
I duplicated the original once more and inverted the new layer. Then set it at the top of the stack. Then applied levels to this layer until I could clearly see the differences in the skin tone. I then set the active layer to the gaussian blurred layer and used the inverted layer as a guide for the spot healing brush, burn tool, and dodge tool - removing any rogue freckles, and evening out the redness under the eyes. .
Hmmm...what did I do next...
When I was done shaping out where I wanted the freckles to show (on the chin and under the eyes) I deleted the inverted layer. Then whitened the teeth (you can find tutorials all over the place for this), redened the lips, whitened the eyes.
I used the quick selection tool to pick up the yellowish area around the eyes, then applied a feather to the selection via the "refine selection" dialog. and used levels, curves, and hue/saturation to bring it closer to the surrounding flesh tones.
I finished up with a few adjustment layers, such as curves, levels, hue/satration, colorbalance, etc.
Use your words like arrows to shoot toward your goal.