Career Bliss.com – General comp information about a wide variety of industry sectors and jobs within them. Also provides views from employees about companies (although I think these tend to be inaccurate and skewed - frequently these comments are dominated by the unhappy employees who vent).
Careers in Business – General business areas, jobs, salaries, and employee opinions (for skeptical commentary about this latter aspect, see above).
Economic Research Institute – Salary surveys based on title and industry. Be careful here, in that titles have wide variance from industry to industry and even company to company within the same industry.
Glassdoor.com – The best known of all the salary websites. Employee reviews (again, don’t take these too seriously), and salary details about specific jobs for various employers.
Greenbiz.com – Salary trends among sustainability professionals.
Higher Ed Jobs Salary – Salary trends reported by HR professionals in academia.
Indeed.com – Another very well known salary site. Wide-ranging; look for “salary” on the bottom of the cover page and click through.
Job Star Salary Guide – Comp surveys by profession.
Professionals for Non-Profits – Annual Salary Survey Report for nonprofit positions, mostly in Northeast US.
Salary.com – “Salary wizard” will give a free base salary, bonus, and benefit report based on job title and location.
Wall Street Journal – Salary and hiring information.
Workforce Management – Comp trends and research tools.