How to read Linux kernel ??

How to read Linux kernel ?? -- Linux general technology-Linux technology and application information. For details, refer to the following section. {: 2_92:} the younger brother wants to study the Linux kernel. I feel no direction !! I have run the 2.6.38.3 kernel source code and a sourceInsight. I don't know where to start. Can you give me some suggestions ??? I borrowed a lot of books from the library to introduce the kernel !! Up to now, the kernel source code does not understand a word !! What route should I take ??? {: 2_103 :}