From the Apple Menu, System Preferences

Click on Networkicon in the System Preferences

Click on the Assist Me... button

Note: your screen will look slightly different based on your configuration.

In the Location Name box, enter "Maine Internet Service" to identify your connection.

Press the Continue button...

Select I use a telephone modem to dial my ISP., click Next

then press the continue button.

In the Account name box, enter your login name with the network extension; provided by Maine Internet Service, it will appear something like  "loginname@c-dial.us”.

In the Password box, enter your Password.

In the ISP Phone number box, type in your local access number,

then press the continue button.

Choose your modem

then press the continue button.

Verify your Settings

then press the continue button.

Click on the Connect button

This will bring up the Internet Connect Dialog

Once you have configured your system, connect by clicking on the modem in the menu bar and selecting the Connect menu.