Well, that's really no that hard at all...
First, call Image->Adjustments->Levels (CTLR+L), and play with white point and black point. In this case i just moved the white point to the end of histogam (you'll understand when you'll see it) to make the photo look more lit.
Then, go to Image->Adjustments->Shadow/HighLights and let it enhance the shadows. Move the slider as you feel it would be right.
There is also Bightness/Contrast setting there in the same menu, it is useful sometimes too.
And another thing in Saturation (CTRL+U) that you might want to correct.
Generally, for most cases, that's all.
If you will shooting RAWs, then there are similar (but more accurate and more versatile) settings in any RAW canverter... Can't REALLY explain things about RAWs, because i myself am not used to them yet...
Hopy you'll be able to get what you want