Bureau of Labor Statistics
The Bureau of Labor Statistics provides a wealth of information in most demographic and economic categories, including population, wages, education and skill levels, unemployment rates, and many others. Information is provided on both a national and regional level. An essential source for the evaluation of potential labor pools.

Census Bureau
The Census Bureau provides a great deal of information relating to population, business and geographical statistics. Current data as well as essential projections for the future are available.

Bureau of Economic Analysis
The Bureau of Economic Analysis provides valuable economic information on gross state products, state and local personal income and employment, and short, computer-generated narratives describing personal incomes in states and counties.

America's Job Bank
America's Job Bank is a partnership between the US Department of Labor and the state operated public Employment Service. Its employer services include job postings, resume searches, and job market information such as wages, trends, and geographic profiles.

The Right Site
This site offers an exhaustive list of free and easy to use demographic reports based on US Census data sorted by geographic and demographic variable.

Big Picture Web Demographics
You can find recent studies here on who is using the internet and what they are using it for.  It may provide information relevant to web recruiting or provide inspiration for web recruiting projects.