I just got a great tip from a consultant I met. Go to visitloudoun.org and apparently they'll help you with
1. Finding venues
2. Booking hotels
3. Getting info on Loudoun for your out of town guests.
I was really excited when I found this out and thought I should share!
Good Luck!
(I emailed the lady who's the coordinator, but haven't heard back yet, so we'll see how it goes)