The Better Business Bureau suggests you do some homework before deciding on a particular provider. The first thing to look for when choosing an ISP is whether they have an access number that is a local phone call for you. If you reside in or near a large or medium-sized city you should have no problem finding an ISP with a local access number. However, if you live in a rural area you may not have much luck in finding one at all. If you can't find an ISP with a local access number, be sure you get the best long distance rate possible.
Most providers offer a monthly fixed, flat-rate with unlimited online time.
Keep in mind, that the lowest price is not always the best deal. Find out what features are included in the price, such as e-mail, Web page hosting, filters for downloading, etc. If you're new to the Internet, you should look for an ISP that will help you get things up and running. Call the number at a time representative of the hours you'll be keeping and see how often you get a busy signal or get placed in a queue, and for how long. If you already have Internet access, check out the company's web site and see how informative it is and how easy it is to navigate.