What kind of properties surround the property you intend to buy or sell?
Is neighborhood deteriorating or getting better?
Are large chains stores and grocery stores planning to come to the neighborhood?
Number of "for sale' and 'for rent" signs. Having more owners is better than more renters.
Condition and maintenance of streets.
Quality of cars. New and well-maintained cars are a good sign.
Age of houses in the area.
Crime statistics.
Rating of schools.
Hospitals, shopping centers, fire stations, police stations, sporting facilities, recreation parks in the area.
Access to public transportation and major arteries.

U.S. Department of Housing and Urban Development has good information on home neighborhood network.

How to check the neighborhood

Speak with a real estate agent specializing in the area.
Search the Internet for demographics, crime statistics, school and hospital information.
Go to public library and ask for local information.
Talk to neighbors around the house that you plan to buy.

Home neighborhood tips

Large retailers, grocery stores, shopping center developers hire people to make researches for their new locations. Their researchers take into consideration all statistics, demographics, crime statistics, etc. So, try to get leads about their future moves.

See how many stores they already opened and how many they are planning to open in the near future.

Local zoning and planning department may have growth and zoning plans that you may look at. Ask for last public meeting records.