Here's a quick photoshop tip to help you brighten up a dark photo. If you're new to photoshop and are intimidated by the Levels and Curves command then I think you'll like this simple technique.
Brighten A Dark Photo in second part of post...
Step #1 - Add Adjustment Layer
At the bottom of the layer palette, click the adjustment layer button (it looks like a circle that is half black, half white) and add an adjustment layer...it doesn't matter which one. I chose the 'Levels' adjustment layer.
A new dialogue box will pop up. Without making any adjustments simply click OK.
Step #2 - Change Layer Blending Mode
At the top of the layer palette change the layer blending mode from 'Normal' to 'Screen'. Voila!