If you intend to connect to the Internet via ordinary phone lines, courtesy of your Mac's built-in modem, you need to sign up for an Internet service. Hundreds of companies, large and small, would love to become your Internet service provider (ISP), generally charging $20 per month for the privilege of connecting you to the great Internet.
A setup program for EarthLink, a popular ISP, presents itself as part of the Setup Assistant program that runs the first time you turn on a new Mac.
But if you aren't starting in such virgin territory (or if you want to sign up with a different ISP), you must plug a series of settings into the Network pane of System Preferences. You'll need to get this information directly from your ISP by consulting either its Web page, the little instruction sheets that came with your account, or a help-desk agent on the phone.
The following instructions don't pertain to America Online. It comes with its own setup program and doesn't involve any settings in System Preferences.
Start by opening System Preferences and clicking the Network icon. You're shown the view pictured in Figure 19-1: a Network Status screen that summarizes the various ways your Mac can connect to the Internet or an office network, and how each connection is doing.
From the Show pop-up menu, choose Internal Modem. (Or just double-click the Internal Modem "row" of the status screen.) You should be facing the PPP tab, where you fill in the blanks like ...