Hey, i am trying to install my wireless 'Atheros Communications, Inc. AR5212 802.11abg NIC (rev 01)' in fedora 3. The manuals i've read said that i needed to install the madwifi package. Now, when installing, i tells me to install this thing:

Error: Missing Dependency: /boot/vmlinuz-2.6.12-2.3.legacy_FC3 is needed by package madwifi-kmdl-2.6.12-2.3.legacy_FC3
Error: Missing Dependency: /boot/vmlinuz-2.6.12-2.3.legacy_FC3 is needed by package madwifi-hal-kmdl-2.6.12-2.3.legacy_FC3

So, i went ahead and downloaded the following rpm:
kernel-2.6.12-2.3.legacy_FC3.src.rpm

But when installing this thing, i get like a hundred lines of the following two lines:
warning: user mockbuild does not exist - using root
warning: group mockbuild does not exist - using root

Now, evidently it's not working, how can i get this installed so i can continue with my wireless conquest?

you have only installed the source (src) not the actual rpm itself. you need to use an i386 / i586 or i686 rpm, not an src.rpm. OR you learn to install source rpm's, which you don't need to know really anyway.