Linux kernel network stack

Hi all, I am looking to start Linux kernel network internals. I know a good book "understanding Linux Network Internals". I need something very quick to start with and remain it as reference in by library. I had gone through some online resource, which gave me very good start to work on. Now I want to delve little deeper in to kernel code on network internals side. Especially I want to learn step by step data path in kernel to user space, and how various protocols and wireless stack glued together. Can anyone please point me to moderate explanation book or online resource. Thanks in advance -- Regards, Sri.