Photo manipulation and Touch-ups.

For this tutorial, a version of photoshop above 7.0 is recommended.

Mini tutorial 1: Skin color.
Here we are going to use a picture of a girl. As you can see, he skin is pale, and she looks like she wears about 100 pounds of make up. We're going to add some life to her face.

The easiest way (which is quite complicated for beginners) is to toy with the levels.
This will fix the lighting in the background which corresponds with the lighting on her face. To open the levels menu, simply hold CTRL and press L.
This should open something similar to this:

Now, to move the small Grey pointer (

) to the right until you get the color back to her face. For me, it came out like this:

You can now see her rosy cheeks, her eye color, and her lips even look a little fuller.
Ta daa!

Mini tutorial 2: Funky eyes.
For this tutorial I'll teach you how to edit eye color to make the image look more interesting ( or for the fun of it, which is why I do it sometimes ). I'll be using the same girl picture. First off, zoom in on the eyes (keep zooming in until you can make the exact detail).

Now, grab the "Lasso Tool" (the little rope that's in a circle) and highlight the pupil of the eyes, which should loook like this:

The trick is to get the whole area that has color to it. The image above should be a good enough example.
Now that you have it highlighted, press CTRL+U to open a new window. Click the "colorize" button. Now, fool around with the saturation and hue tabs until you get a cool color. This is how mine came out:

Do it for both eyes and you'll get a kicken picture. Ta daa!