You've probably heard that the federal government is the nation's largest employer, and it's also true for Virginia. There are government jobs everywhere, especially when you also consider state and local government opportunities.
Some of the sources listed in this guide will still help you in your research. For example, the Vault also includes a government industry report and profiles for related companies, industries, and government entities.
You will also need to consult some specialized sources. Here are some starting places.