#KERNEL
At this site, you can get a lot of free material. Indeed, this site exists primarily to supply you with free samples as a means of encouraging your attention.
This is the top level of the kernel's documentation tree. Kernel documentation, like the kernel itself, is very much a work in progress; that is especially true as we work to integrate our many scattered documents into a coherent whole. Please note that improvements to the documentation are welcome; join the linux-doc list at vger.kernel.org if you want to help out.
Take a look into the depths of Windows kernels and reveal more than 60000 undocumented structures.
Combat in the kernel space -Its Pointy and it HURTS!