Sit back relax and enjoy the ride
You do not have to prepare to much. The number of information is not to overwhelming, I bought panel posters, additional study materials before my own typerating course, which i really didn't need when it came to it.
Use the before mentioned website and look through the 737 panels to get to know roughly where the different systems and knobs are placed on the panels. Also read about the main systems; pressurisation, electrical, flightcontrols, hydraulics and fuel, to get to know the basics of these systems.
The sim sessions are great fun, but the top of the cake is doing the basecheck on the real aircraft (when you haven't flown a big jet before), actually the 737-500 i flew for my basecheck was the only real aircraft I flew all last year, 5 good landings and 1 so so .. pretty good!
