Is there a good, succint link for information on pH testing and adding lime if necessary?

Recent Lime Thread

That is a recent link with some good information.

Ask a couple of your local farmers or maybe the county ASCS office how much lime is required in your area to keep crop fields at a desirable pH level.
Adding lime to your pond at the same rate will get you in the ballpark.

Texas A&M University is the place to go for water testing.

TAMU Water Testing Lab