The Multiple Listing Service
Even before the sign is up and the brochures are ready, your agent should list your property with the local MLS (Multiple Listing Service). The MLS is a database of all the homes listed by local real estate agents who are members of the service, which is practically all of the local agents.
Important information about your property is listed here, from general data such as square footage and number of rooms, to such details as whether you have central air conditioning or hard wood flooring. There should also be a photo, and a short verbal description of what makes your house "special."