I'm still learning too and I find it extremely helpful to see other people's pictures and try playing with them. I have gathered a number of photoshop actions (you can download them from my web site) that help images - for your image, I started by making the image a bit more contrastly using Levels and then used the LocalContrast Action which brings out detail in non-contrasty images. I then added a bit of Lab saturation. Finally there was a fair bit of noise, especially in his trousers, so I used NeatImage to remove it.
I'm slowly coming to the conclusion that post-processing is almost as important as get the shot right in the first place - so practising on lots of different images helps one learn quite fast. Have a look at how I did my "Wow" picture to see what I mean - I started with a dull picture and managed to change it into something quite interesting.