When negotiating salary with HR (or as HR) for a software engineering position, what sources do you usually rely on for numbers about market salary and total compensation?

Sites like glassdoor/payscale/salary.com/indeed give numbers, but they do not make it clear how old the data points are, how many they include. They also do not account for biases of self-reporting by employees or companies.

In the US, the Bureau of Labor Statistics gives general information[1], but since their numbers are often a couple years old.

Are there any good sources you would recommend? What about for large cities outside of the Bay Area?

1. http://www.bls.gov/ooh/computer-and-information-technology/software-developers.htm