I have become a huge fan of Indeed.com.

Now they have a Salary Search. I pulled some info right from their web site to explain what they are doing. This is a great tool to figure out how much you are worth.
Indeed Salary Search is based on an index of salary information extracted from over 50 million job postings from thousands of unique sources over the last 12 months. Many job descriptions don’t contain salary information, but there are enough that do to produce statistically significant median salaries for millions of keyword, job title and location combinations - in fact, most job searches you are likely to think of. As new jobs are added each day, the Indeed Salary Search index is automatically updated with fresh salary data, so the salary results are as up-to-date as they could possibly be. (Credit:Indeed.com)