For a quick overview, I like http://www.makelinux.net/kernel_map/ http://www.makelinux.net/kernel_map/ - even though it's a bit dated (the map mentions kernel 2

For a quick overview, I like http://www.makelinux.net/kernel_map/ http://www.makelinux.net/kernel_map/ - even though it's a bit dated (the map mentions kernel 2.6.36), I find it a good starting point for digging deeper.