I love the BVI's and there are any number of good charter outfits there. BUT...I would not go there from 12/10-12/24 as you will be in PEAK PEAK season and fighting other boats for the moorings wherever you go. Realistically you will have to be at your evening anchorage no later than 2pm to get a spot. If you can wait a month or two and not do it during a school vacation period, you will enjoy yourself more.
If the time period is fixed...possibly consider a less crowded area...The Abacos in the Bahamas are wonderful as are the Grenadines (though a bit more difficult for beginners...don't know your comfort level with Christmas Winds/Seas down there. ) Moorings has a big fleet of monohulls and Catamarans in the Abacos...there is plenty to see and do there and the water/reef life is beautiful BUT you can easily get a "cold front" that will drive temps into the 60's in December...kinda like south FL.
I can't think of a better place than the BVI's but if you can switch your dates a bit, you'll get a much better experience.