This is a magnificent site, perhaps the most interesting in China. We went in December and had the place virtually to ourselves. It's cold inside the museum, so dress warmly and wear comfortable shoes. If you read a little online before going you won't need a guide. I arranged for a car and driver from the Sofitel which insured a smooth coming and going, 600 RMB for the trip. You'll be very sorry if you try to visit this museum in peak season, it will be a madhouse, and you'll be bumped and jostled and not see much. We were able to linger, move at our own pace, and just really enjoy everything.