The Occupational Outlook Handbook is the government's premier source of career guidance featuring hundreds of occupations—such as carpenters, teachers, and veterinarians. Revised every 2 years, the latest version contains employment projections for the 2012-22 decade. (Description from website)

O*NET OnLine has detailed descriptions of the world of work for use by job seekers, workforce development and HR professionals, students, researchers, and more! O*NET OnLine is sponsored by the U.S. Department of Labor,
Employment & Training Administration,
and developed by the National Center for O*NET Development. (Description from website)