Air temps should be in the 80's or 90's. Water temp should be right around 70 give or take a few depending on the weather the week before. It's a great lake, but just like every place, it gets busy on the weekend. Are you camping or house boating?
The lake is really deep, and there are very few obstacles to watch out for. The only thing that I can really think of is a patch of rocks near the main ramp. It's well marked with buoys on all sides though.
Here are a few pics I found from google. It gives you a good idea of what it's like!