toddle off to freshmeat.net and get pureftp
are the users using the box as well or just web publishing?
if they are just web publishing then the way to do it is as follows
setup the users with their homedir as $pathtotheirwwwdir
set the passwd for the users
install pure-ftp
run pureftp with -A -B -E
then when the users login via ftp they will automatically be dumped into their www dir
and with he -A option set they cant go anywhere else because that chroots them into that dir
Linux its better than women :P