These associations often offer discounted membership rates for students. You'll also find current information and publications relevant to HR professionals:
Bureau of Labor Statistics (BLS) -a great source for information on employment statistics, job outlook data, and more.
Data.gov -a portal to all sorts of government data.
OSHA's Statistics & Data Page -worried about workplace injuries and interested in employee safety on the job? Take a look at OSHA's data.
O*NET -not technically a government but an excellent resource for job descriptions.