I would download and install the package linux-source-3.0.4_3.0.4-10.00.Custom_all.deb. This will give you a tar archive with the kernel sources in /usr/src. After extraction you will have a new subdirectory tree with all the kernel sources.

I would suggest that you start with
Code:
make oldconfig
and
Code:
make menuconfig
This enables you to examine the current configuration of the Linux kernel.

You can read more on the Debian-Knoppix mailing list about how Klaus Knopper compiles a Linux kernel for Knoppix: Re: Problems trying to recompile the Linux Kernel 64 bits on Knoppix 6.7

I think you have to install some more packages like fakeroot and make-kpkg using apt-get.