Will you be visiting Historic Williamsburg or Water Country as well? If so, look into the Bounce Pass. It's a 7-day pass for all three - and includes parking at BG and WC. I think they have a new Flex Ticket, too, that covers Jamestown and Yorktown. Under age 6 is free, too, even though there's a charge for over 3 at BG, so it's even a better deal if you have kids in that age range.
We did the bounce pass last summer and it was great. We didn't feel we had to cram everything into one day. We also went to Water Country USA one evening, which usually isn't our thing, but it made for a pleasant time and, hey, it was free with the pass.