After you have duplicated the background layer by dragging it to the new layer icon, you can now make some adjustments to the selection we've created in the previous tutorial.  The selection will remain in place while you duplicate the layer.

Go to Image: Adjustments: Levels. I'm going to give you a basic idea of what's going on with levels.

Since we have made a selection on a layer, when we make any kind of adjustment it's going to apply only to the selected area. If we hadn't made a selection, the adjustment (through this method) would apply to whatever layer that is selected in the layers palette. Adjustment layers (which are more disposable) are fully covered in the Basic Photoshop DVD program.

With the levels dialog box open you can drag the sliders to the left or the right. The black filled slider on the left is black because when you drag it to the right you start mapping the light values (of the selected area) to black or darker.

When you move the white slider to the right, it is mapping the tonal range or light values to become lighter.

One way to increase contrast with levels is just to pull both end sliders in a little towards the middle which increases both the dark and light values, hence the higher contrast. You can always use Image: Adjustments: Brightness Contrast if you aren't yet comfortable with levels. The grey slider you can move to increase or decrease grayscale contrast towards darker or lighter.

Levels gives you a lot of control as you can also adjust the individual lightness values of each channel (also covered in the Basic Photoshop training).

Now you should have a good understanding of the basics of using levels to increase light or dark values or contrast of a layer or selection.

If you want to finally just want to become proficient in (literally) everything Photoshop has to offer then you'll want to grab the Basic Photoshop training which is my video training for Photoshop beginners. It also covers many intermediate techniques to get you fully versed in using and understanding the power of Photoshop. It's over 8 hours of pure Photoshop training at a third the cost of the competition.

Note: the histogram in levels will not change until you press OK and then open it again, if you're wondering.