It looks like your sky is burned out a bit too much - I suspect you will have to replace that - any adjustments will just adjust the white (to grey etc.) as there is no other info left to adjust
You can use the Dodge and Burn tools to adjust areas using a brush, and you can adjust the curves and Levels, Exposure, Gamma, Saturation on selected areas or the whole photo. Best way is just to have a go - look under the Images > Adjustments menu.
If you want to play with the photo, it is best to originally save it as a RAW format (12-14 bit) on your camera where possible .. which has a greater dynamic range, and hence scope to adjust your exposure to view (saved) details - using Photoshop or a supplied RAW editor. (
http://en.wikipedia.org/wiki/Raw_image_format)
I play around a lot with HDRI (32 bit) for CGI. And you can build those up in Photoshop by taking many identical photos but with varying exposures - look and see if your camera has a bracketing function (Although for bests results you need more than 3 differing exposures).
D.