First make sure your modem is properly connected to the power supply and the modem is connected to the telephone line.

If you want to enable any user to be able to dial out with the modem, the the following command while you are logged in as root:

chmod o+rw /dev/ttyS*

This command gives all users access to the dial-out devices.

Now edit the text file /etc/minicom.users and add a line with the word ALL to enable all users to access the minicom configuration.

If you don't know how to do the able here are the steps:

Type - cd /etc <enter>
Type - vi minicom.users <enter>
scroll down the page somewhere in the middle, doesn't matter where, press the insert key once, press enter once, you will now see a blank line,
Type - ALL
now press escape key once. hold shift key down and press the column key once.
Type wq <enter>
The changes should now be saved, and you will have exited out of vi.

Next to enable any user to read from and write to the serial port where the modem is connected. For example, if the modem is con COM1 (/dev/ttyS0), type chmod o+w /dev/ttyS0 to give everyone write permission for that device.

If you modem is on COM2, change the command to chmod o+w /dev/ttyS1

Now you will need to establish a link between the /dev/modem and the serial port device where the modem is connected. If the modem is on /dev/ttyS0, you should type the following command:

ln -s /dev/ttyS0 /dev/modem

Now you are ready to start the dialing program, type the following:

minicom

When in side the program, press Cltr-A to get the attention of the minicom program. After you press Ctrl-A, if you press Z, a help screen appears in the form of a text window.

Now press D for dialing directory.
Add the number you wish to dial, give it a name such as My ISP, and press dial.

Simple!