Learning to build kernel

Folks;
I want to learn kernel building. In a practice mode. So I figure, I can't 'install' the 2.6 sources, since that would overlay the valid headers I have (Linux lp2 2.4.24-xfs #1 SMP Mi Feb 4 01:03:50 CET 2004 i686 GNU/Linux) in /usr/src.
Maybe
'dpkg --root=/practice/ -i kernel-source-2.6.5_10.00.Custom_all.deb'
and then follow the other instructions.
Since these two kernels don't match, will running the instaled makefiles make dangerous assumptions about locations?
How would I test a new build? Just to see if it would boot? What other pieces need to be updated to be in sync with a kernel version?

BillS
:?: