Building zd1211 drivers fore WiFi dongle

Note.. I posted this same query in the nabble nslu2-linux forum. Someone there suggested I try here as well. tnx

Folks.
I'm a total newb in both the debian and slug worlds... but I'm already having a blast... and want to get fluent in these things.  Right now I'm trying to get a zd1211 based wifi USB dongle working with my slug using the instructions here  . I poked around some and learned that someone had built the zd1211 drivers in a package called zd12111-firmware. When I try to install it I get

LKG7CD387:~#  apt-get install zd1211-firmware
Reading package lists... Done
Building dependency tree... Done
Package zd1211-firmware is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package zd1211-firmware has no installation candidate

I looked further and found a package called zd1211-source, which I downloaded. From what I can tell, that gave me a file called zd1211.tar.bz2 in /usr/src .. Now, I suspect that  most folks know what to do with that type of file. I'm sure it's a source tar file of some sort, , but I don't yet know how to unpack it,modify it for my system config,build it and install the drivers it creates. . Is there some sort of 'Building drivers for dummy's' anywhere ? I've searched the web and this forum but most of the info assumes more knowledge than I have.  I'm eager to learn...but I just need a pointer in the right direction. Any help much appreciated ...

-jc