If you are learning about Linux Kernel, then first thing you have to learn is the structure of Linux Kernel. It consists of a lot of layers and within one layer, there are a lot of subcomponents within. Sometimes you might get lost, but thanks to the Interactive Mapping of Linux Kernel, it has become easier for newbies such as me to learn more about Linux Kernel and find the related documentation about it.
So help yourself by bookmarking this wonderful site if you are planning to learn more about Linux Kernel. Don't forget to use KernelNewbies as well as as one of the resources. It has a lot of good articles for starters.