You don't need a server with mindspring, they will allow three logins at the same time with their DSL package. Connect your modem to the uplink port on your hub, along with your computers. Put your mindspring software and firewall software on each computer and login using the same account info and password on each one. You will be assigned three different dynamic addresses. If your network grows to four computers you'll have to set up a server, or buy a router.
If you connect the modem to a hub all machines can access the modem and then the internet connection but only ONE at a time (no sharing of the internet connection.) With a router ALL machines can access the internet at the same time through the router. The router supplies the internet connection. Now some routers also have an auto sensing switched hub built into them. But you can connect the router to a switched hub is best if you buy one with only one port on it. Also when you run more computers than there are ports you can uplink other hubs to it. The router also provides a hardware firewall for your computer. The configuration is; ADSL Modem /Router (/Hub if you need one) /Networked computers NICs. I use a Linksys Router BERSF41.
In my case (I have 2 systems, a 3com hub, and a Cisco 675 dsl modem which provides NAT) I just plugged the Cisco into the uplink port of the hub (in this case using a crossover cable provided w/ the Cisco) hooked my systems to the hub and bingo, there you go. So.. I assume from your question that your DSL modem is external, if so, does it provide natting or some kind of proxy service? If so, you can probably do the same thing.
My setup is very similar to yours:
DSL modem connected to hub (with crossover cable) Two Macs connected to hub (with regular ethernet cables) LaserWriter Pro connected to hub (with regular ethernet cable)
All devices are plugged into the normal hub ports - the uplink port is unused. I have a PPPoE client (EnterNet) and firewall software (DoorStop) on both Macs.
This setup works fine for me. Both Macs see the internet and the printer and each other.
Note: the hub will broadcast your local network traffic (printing, file sharing) onto the internet. And, if you do not have firewall, it might be smart to disable file sharing and web sharing on these Macs when the DSL connection is on. A more secure solution is to replace the hub with a router (LinkSys, Xsense, etc.)
-- Julian Vrieslander <mailto:julianv@mindspring.com>
http://www.tuketu.com/dsl/xdsl.htm
CAT5 Cross-over Cable