Information on Dragoncon 2006 will be up on their website in a month or so. A few snippets just for the curious, though.
If you want to stay in one of the hotels actually hosting the convention, Jugs has the right idea, they fill up early, and people do book their rooms for next year just a month or two after this year's convention. Check
www.dragoncon.com regularly for details. The hotels (the host hotels for 2005 were (as in many years past) the Atlanta Marriott Marquis and the Hyatt Regency Atlanta along with our new co-host hotel, the Atlanta Hilton.) are high class and very expensive, though, even for single rooms.
The DJs this year stayed in the Residence Inn, it was just a few blocks away, easy walking distance, and very affordable. The suites we stayed in sleep 3 comfortably (2 on a full/queen bed, and a rollaway bed). The windows are painted shut, however, even in smoking rooms, so it gets stuffy really quick. There is a sink, a stovetop, a dishwasher, a microwave, and a fridge (full size, even!) in every suite. All in all, it was a great place to stay.
The price of Con admission is always going to be around $100. (I think this year it was $80?), but it's cheaper if you Pre-Register before May, so I heartily suggest that you do so.
Dragoncon is also always in Atlanta, it's not a touring convention, and it's been held in the Hyatt for as long as I can remember (with additional hotels being added as the Con has grown). So if you have friends in/around Atlanta to stay with, that's another option.
Hope that answers some of your questions, while the answers are fresh in my mind. It never hurts to think about these things early!