Pond Construction & Renovation

The land we are contracted to buy has a small pond.  I'm quite happy that there is surface water but the pond is one of the few shortcomings with the property.

The following is a picture of the pond from the property listing.

As I said, its nice to have the pond but...
1) The pond is a little on the small side to hold fish.
2) The pond seems a constant tan color from the sandy soil in the area.
3) The water level seems to stay at the height show above even after getting about eight inches of rain.

After we close on the property, I'd like to put some form of measuring stick in the middle to see how deep it is and how much water is lost through the hot summer.  Until then, I'mtrying to learn what I can about making the pond a little better.  A few of the resources I'm looking through are:

USDA Pond Planning and Design

Pond Boss Forum