Kernel documentation and specification

[klowd9 -]

Where can i find resources about the freebsd kernel?
I read over the developers handbook, and the architecture handbook, and both 
provide very little information i need.
Also if anyone can recommend irc channels to visit where developers are to 
be found.
I visited #BsdCode of efnet, but it was keyed not too long ago.

Some questions for instance are the use of sse, mmx, and fpu register and 
commands inside the kernel. How is the development organized. Is it just a 
jungle where people choose what they want to improve and expand in the 
kernel and then submit their code?
What type of process scheduling the freebsd uses, interprocess communication 
and more..