-- Last Updated: Jan-30-13 7:56 PM EST --
For waters from 50 up until your comfortable (probably somewhere in the 60s) is a 3 mm farmer john. A paddle jacket is an excellent addition, as wet suits don't do much for wind protection (though you could possibly use a non-paddle specific wind breaker in place of this at first). With these two, and added base layers of polypro, wool, or similar (often clothing you'd use for pther exercising, like hiking, biking, etc) you can deal with a pretty good range of temps.