Run by Mid-Atlantic real-estate firm Corus Home Realty, Realtyinstitute.com offers a wealth of information about Washington-area neighborhoods and real estate.

The site produces hundreds of neighborhood reports organized by Zip code. Each serves up interactive maps, sales-price data, and demographic information such as median household income and population. For-sale listings are broken down by type—condo, townhouse, or detached single-family home—and price. Reports include links to articles about the neighborhood and the chance to talk with a “neighborhood specialist,” a local resident who’s volunteered to chat with potential buyers.

Another useful feature is the “Realty Institute Index,” a rating of the real-estate market for each Zip code. Taking into account the previous month’s sales activity, the index rates the market conditions of neighborhoods from cold to hot.