Fred, welcome to TS! (BTW - you might want to change your ID - using your email address will probably produce a flood of spam from web spiders that automatically scan web pages for email addresses. I see that you may have purchased a domain just for this online purpose...but putting an email addy on a page like this is a surefire guarantee of future spam floods)
Have you got a router in order to share the cable connection?
You should be able to go into the TCP/IP control panel and set it to "ethernet" and "configure via DHCP" and be all set, if you have a router (or even connecting directly via the cable modem)
The "shawmail" settings you refer to are probably your email settings, which, unless you want to be able to send email on this old Mac too, you won't need to bother with.
Once you get the old Mac connected to the internet, it should be a simple matter of setting up file sharing (setting passwords and privileges etc.), turning on AppleTalk and then from the Chooser, selecting AppleShare...(assuming that you have a router to connect both machines together and share the cable modem) There are other ways to connect them too, via ethernet crossover cable, but you wouldn't be able to connect to the internet AND the other machine this way, as there is only one ethernet port.