Thanks all. I had only read Scott's responses before I left, but these tires have a max capacity of 51psi.

I decided to go with 38.5 in the front and 36 in the rear. This was after driving on the freeway for a couple miles, but I'm going to assume the tires were "cold".
Does that sound okay to start? I'll definately check them after/during the first run to see how they do. Thanks for the chalk tip Dean...I always wondered what those triangles are for.