I'm not an expert in that area, but wanted to point out that there's the start of a trail that will run from Williamsburg to Richmond at some point. Route 5 is also quite rideable. There are some good back farmroads that cross Rt 5 also.
Here's the Cap2Cap site:
http://www.virginiacapitaltrail.org/
You can probably find some cue sheets for the Cap2Cap ride on mapmyride or similar sites.
I've also ridden on the Jamestown site, but the roads are extremely rough despite being paved. Would be fine on a cross bike or a hybrid, but a little bone-jarring on a road bike. Same thing goes for riding the Colonial Parkway, but it's not too bad if you let a little air out of your tires
I sometimes trek down that way in the wintertime when I see by the weather reports that I can miss a snow storm, or get a 10-degree temperature warmup.