Strictly, if you want to compile a kernel, you don't need to know how to
program in C! In src/sys/arch/i386/conf are kernel configuration files. You
probably want to
cp GENERIC MYPC
edit MYPC to suit your computer
config MYPC
cd ../compile/MYPC
make depend && make
This will create a file called netbsd which is the new custom kernel.

Cheers,

Patrick