Nashfireman,
This is a great site for soils. Obviously there is no substitute for digging your own samples but one thing I liked about this site is it allows you to see what type of soil is under your neighbor's ponds. You can look for sites similar to your's nearby and talk to those folks about their construction.
Good luck, I know of a lot of nice ponds in your part of Middle TN.
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
