Setting up a network

I have been given the duty to setup our network. I am not a network administrator or any of the such. I do know a little about tcpip and some other configuration settings. Our existing setup is as follows. We have a Efficient Networks speed stream 5100 DSL modem which is plugged into a linksys BEFSR41 router, which is plugged into a Dell Powerconnect 2324 Unmanaged switch, which all XP sp2 workstations & win 2003 Small business server standard are plugged into. I basicly plugged everything in and it worked. Now I am wondering if I set this up correctly, or if I could set it up to be more effecient. Maybe connect it differently or some thing. I also would like to be able to moniter our users.