If I make a reservation with a debit card, will it be charged immediately?

Yes it will be charged for 1 night.

When making a reservation, the hotel will charge one full night, plus possibly more to cover incidentals (telephone calls, etc) This money is taken immediately out of your account. If you do get a refund, it will be given back to you, but generally take a week or two for processing. Also once you check in, they will place a hold on the card for the full amount of the room, plus additional for incidentals, and this money will not be available to you until you check out, when the hotel removes the hold and the actual costs are then charged to your room.

For this reason, Furry Weekend Atlanta recommends that you do not use a Debit Card when booking a hotel room.