Before doing this, and possibly wasting your time by having used a bad install make sure you've installed it, word for word.. line for line from this:
If that doesn't load it:
*Didn't for me, didn't know what driver to put where it tells me to, when you install it from that, you'll understand what I mean. Use hwsetup from below to see what driver you need, and the add that in*
That solves many things, but didn't fix my network card.
My way of finding things out is to use a part of knoppix. hwsetup
hwsetup -n |less
And look for the network driver
Then run lsmod and make sure it's loaded
If it's not, run, modprobe <driver name>
If it loads fine, meaning now it shows up on lsmod then add it to autoload
Edit the file of the kernel you are loading, mine is kernel-2.4 (I recommend starting with 2.4 and then going with 2.5-2.6 if you want to have their features, 2.4 is stable)
Add at the end of that file, the name of the driver hwsetup told you to, nothing special, just on a new line.
After that just restart.
If that doesn't work, as in modprobe didn't load it, then what you need to do is look at the logs of your kernel.
Look at /var/log/kernel, or whereever your particular logger keeps it's files.
Post the error message here, and we'll try to help
Good luck! and tell us if it worked