If you want to spend more time in the USVI, you should target St. John. Check http://www.nps.gov/viis/planyourvisi...oringGuide.pdf
for boating information, but your major choices involve the north side of St. John, from Lynd Point to Leinster Bay, and the south side, primarily Salt Pond and Lameshur Bays. Salt Pond Bay has a nice beach, sea turtles and a 1.5 mile hike to Ram Head, and is one of my favorites. The north side can be subject to swells--something you want to be aware of in the Virgin Islands--in places like Hawksnest Bay and to the east, as well as the BVI. It can be very difficult to handle a dinghy on a beach that is subject to the swells. You will find that an anchorage can be very rolly when the swell is running and make it difficult to get a good night's sleep. The charter bases can advise which bays to avoid.
You might pick up a cruising guide to the Virgin Islands by the Scotts or Steven Pavlidis. Your charter company will probably have a copy of the Scott guide aboard, but you will find it helpful for advance planning purposes. If you are considering chartering out of St. Thomas, you might allow an extra day to explore Charlotte Amalie. We typically stay over at a guest house type accommodation before heading home.
A final note: We started our Caribbean chartering in the Virgin Island and moved on to St. Martin (including Anguilla and St. Barts) and then Antigua, thinking we would keep moving along the Island chain to South America as time went on. However, we ended up back in the Virgins, which we find more accommodating to bareboaters. You can spend years exploring the USVI, BVI, and Spanish Virgins and not get bored.
As you move further south in the Caribbean chain, you will find higher winds and seas and longer distances between some of the anchorages. We find the winds in the Virgins are generally as much as we want to deal with.