Be sure your ISP has modems that are as fast as yours. Do your surfing in the off-hours. Internet traffic is lighter and speeds will be faster in the early morning and late at night. Early evening hours are often the worst for speed. Your Computer A faster computer is better.
More RAM is better.
Make sure you have plenty of empty hard disk space. This web site also has a nice discussion of factors affecting your connection speed. Explanations as to why phone lines are slower than advertised. The best thing you can do for speed is get a cable modem which uses your cable TV provider. This service is not available widely.