I've heard a lot about informational interviews, but don't have the slightest idea how to actually set one up or run one effectively. I work as an SDET (SDE in Test) in an area with lots of great technical companies, and would like to have a better understanding of how different companies do testing.

I have three sub-questions: Who would I get in contact with to set up informational interviews at a company that I'd like to learn about? How can I make sure the time is productive? And, how do I keep the interview from being a burden to the employee(s) whom I speak with?