If I want to do an ftp install (fc3) from a ftp server on my lan using the boot.iso image, how much of http://download.fedora.redhat.com/pub/fedora/linux/core/3/i386/os/
do I need to mirror?
Depends greatly on what you want installed... If you're doing an 'everything' install, you'll need, well, everything. If you're doing a very selective install, you'll need to determine dependencies on your own and download exactly what you need. My guess is that unless you're doing a minimal install (only CD1 is needed IIRC), that it's probably going to be more time consuming to determine all dependencies, so just download the ISO's, mount those on your local filesystem, and copy everything to a single location.
Better yet, download the DVD iso, and mount that...
-id
