Go to start | All programs | Internet Explorer

It may ask you if you want to set up a connection.  If it does, choose the option with the New Connection Wizard.  If it does not ask you, go to Tools | Internet Options, click on the connection tab, and choose setup.

Every version of the connection wizard is just a little bit different, so here are the values you will need;

Set up connection manually

Use a phone line and a modem or a dial-up modem

Under connection name: North Valley

Under phone number: 560-4015 for Oroville calling area, 486-6900 or 861-9600 for Omak/Tonasket calling areas.  There may be a check box that says something like, "Dial using country code and area code." Un-check this box.

Username & Password: Make sure you put them in with all lowercase letters and no spaces