If you haven't experienced the speed of cable internet you're in for a huge surprise. Utilizing the extra bandwidth of their cable wires, cable companies have the capacity to pump data into your house at rates that are a magnitude faster than the modems of a decade ago.
Cable internet users do share the bandwidth of the line leading to their neighborhood. This can be a negative, particularly if your neighbors are heavy internet users. DSL, a competing internet service does not suffer from this limitation, however DSL speeds typically don't get near those of cable. Unless you plan on regularly downloading large files like home movies this internet speed issue won't be a problem for you.
For many people cable is the only high speed internet option available, as DSL is limited by the distance away from the phone companies central office - the place where the phone line meets their main internet lines.
If you have the choice of DSL or Cable internet, and you don't see yourself as a power user, we recommend you make your decision on price. Watch out for the teaser rates that high speed internet providers advertise. Make sure you're aware of the rate after the low subscription price expires.