How It Works: Contracts
Different hotels offer a different options for reserving blocks of rooms. It's important that you take the time to understand the options in order to secure the best contract for your situation.
In an ideal scenerio, a hotel holds a group of rooms for your guests at a discounted rate, and your guests individually make reservations for the rooms, securing them with a credit card. As the organizer of the hotel block, you sign a contract that ensures that the hotel will hold the rooms for a particular rate. Typically, the rooms will be held until a specific date (anywhere from 2 months to 3 weeks prior to the event depending on the hotel), at which point unreserved rooms will be released for sale to others. The advantage of this sort of contract is that you're under no obligation to pay for the rooms you block off if they are not used by your guests. It is difficult to estimate how many guests would want to stay at a particular hotel (especially if you are offering several options), so with this type of contract, you can feel free to overestimate your room needs with no risk.
Other contracts require you to be financially responsible for unused rooms(sometimes a percentage, such as 85% or 90% of the unused rooms), particularly if the hotel is unable to sell them after they are released from your block. Still other hotels require that you pay in advance to secure a "group rate." Unless there is a particular hotel you really like, there is little reason to agree to a contract that holds you financially responsible for the rooms, since there are many other hotels you can pursue.
Getting The Best Deal
When requesting rates, don't hesitate to ask if they can do better. Rarely is their initial quote the best deal they have, but why would they offer you a cheaper rate if you don't even ask? In my research, I have been pleasantly surprised by the ease with which people have come back to me with better hotel rates. You don't even have to be a real "sales guy" to pull it off -- simply saying "Is that the best you can do?" or "I think that might be outside of my guests' price range, can you do any better?" Often, they will have to check with a manager, but patience is well repaid; I often had hotels come back with rates that were $40-60 cheaper per night. If they can't do better, perhaps they can offer you an upgrade or a complimentary room depending on how many guests you book.
Final Considerations
I highly encourage you to visit the hotels that you're considering -- of course their websites tout their virtues, but won't you be embarrassed if you suggest your friends and relatives stay at a skeevy hotel in a sketchy neighborhood? Keep in mind that many people from out of town might be worried about safety, so it's important to chose options in neighborhoods where they will feel comfortable.
Visiting the hotel is a great opportunity to find out if they offer breakfast to their guests (included or at an extra cost) and what amenities are available nearby. It's always helpful to point out to your guests where the nearest pharmacy and food options are, in the event that they need something while they're visiting.
Another consideration as you reserve blocks of room is where you, as the bride and groom, want to spend your wedding night. Do you want to find a hotel that offers a suite for you and your newly betrothed? Would you prefer to stay at a different hotel from your guests to ensure privacy? Don't be surprised when many of your guests choose to stay at the hotel where you are staying if it's an option.

