Looked around and was surprised to find there really are no detailed howtos. By far the best thing I was able to find was the man page.
On the other hand, for the average user, it's a piece of cake. As I'm sure you discovered, all you have to do is install the source code of whatever module you want, then:
Code:
m-a prepare /* you only need to do this if you've
/* upgraded the kernel since the last
/* time you used module-assistant
m-a a-i <module name>
modprobe <module name>
Of course, if the module is to replace an already active one, it would be a good idea to disable the active one before the modprobe. For a module like fglrx or nvidia, you probably need to go to single user mode for the modprobe.
I don't know if other distros have a similar tool, but it has certainly made compiling and installing a kernel module a piece of cake. I understand that some older modules will not work with module-assistant. Probably not a good idea to use it on Sarge, but any kernel module designed for Etch should work.