1. Try the "agency approach." Who produces the information you need? How is this information organized and disseminated? If you can answer these questions, you can create a much more targeted, focused search.
2. Google like a pro. To limit your Google search to government websites, use the very powerful "site:" search. You can search all .gov websites (site:gov) or narrow your search to a particular agency's website (site:cdc.gov).
These resources are meant as starting points for your research. Keep in mind that statistics at the neighborhood level are not available consistently across the entire United States, and that some datasets and statistical publications may not be produced on an annual basis. If you aren't finding what you need with these databases, a good next step is to find out if there's a local government agency that compiles this data, and either use the agency's online tools or publications, or contact the agency directly to find out if they will make their data available to you.
These resources provide quick, easy access to federal and/or state legislative information, and encourage users to keep up with politics and policy through convenient tracking tools.