Kernel-source

[Rein Mann]

It used to be a simple matter when I was using Red Hat.
I am running Ubuntu 6.06 LTS on a Dell Inspiron 1520
(Yes I've tried Gutsy, but that has different problems)
To install my NVIDIA driver I need to install the kernel headers and sources.
Can someone tell me where from and how to install the kernel source for the
running kernel (2.6.15-29-386)?
When I do a sudo apt-get install kernel-source (with or without the actual
version!) the answer is : 'can't find kernel-source'.
I have not been able to find a clear answer anywhere.
Can someone help please.
Rein