Use the "smbpasswd" program to create linux users & passwords corresponding to the Windows users.
Check if your distro supplies a samba-doc package. It includes three Samba 3 books, including "Samba 3 by Example" which will guide you step by step on setting up several different possible configurations. It may also contain the html version of "Using Samba 2nd Ed.".
Yes, samba swat allows you to configure samba via a browser interface. Before you use it, you need to configure xinetd to allow access to it.
Here is my /etc/xinetd.d/swat file:
# SWAT is the Samba Web Administration Tool.
port = 901
socket_type = stream
protocol = tcp
wait = no
user = root
server = /usr/sbin/swat
only_from = 127.0.0.1
log_on_failure += USERID
disable = no
It is possible that this file exists, and you just need to change "disable = yes" to "disable = no".
Then restart the xinet daemon with "sudo killall -SIGHUP xinetd". This will cause it to restart, reloading the config files.
Now point your web browser on the server to "http://localhost:901".