Wikipedia, while not officially sanctioned by anybody, is a great way to keep up with rapidly-changing technology, such as Centrino. They have a good discussion of the new Intel Core Duo and Solo products: http://en.wikipedia.org/wiki/Core_Solo

If you have a few days to spend, follow a few of the links on this very comprehensive repository of CPU-related sites: http://www.techfest.com/hardware/cpu.htm