Chuck Rossi is explaining in a video how the Release management is handled at Facebook; it allows them to push daily updates to their site without production outage or service interruption. This video is very informative and the announced KPIs are very impressive...
watch the video here
While we are talking about release management, I also highly recommand you to dig into the "continuous delivery" book and blogs of Jez Humble and Dave Farley.
Release management is definitively not only about process and tools; it is about changing our culture.