Kernel documentation and specification

[klowd9 -]

>
>Reading the CVS logs for the relevant files should give you ideas
>about who might be able to answer your questions.  However, you
>shouldn't expect that people have time to answer lots of questions.
>Of course, it helps if your interest is in the context of contributing
>something back to the project.
>
>Kirk's book, ``The Design and Implementation of the FreeBSD
>Operating System'' probably contains the answers to basic
>questions about scheduling and IPC.

I considered purchasing that book, which is very very good imo, but a bit 
overpriced at $60..
Any other resources about kernel development, and to whom may i speak with 
to help me get started..