Some smaller shops will read the codes for free and clear them(I know autozone does this), but rarely ever do dealers to anything for free.
I've heard Ford cars need a special scan tool that only ford dealers have to get all the codes. Not sure if this is true or not.
Resetting the code will make it go off temporarily, until you re-start the car and it does another self-check, which will re-trigger it.
If you're in a climate(northern states) that calls for ABS protection in winter months, get it checked out. My *** has been saved from a crash more than once by the ABS system, you don't think about it until you jam the brakes and feel the pedal pulse, keeping you out of a spin. Otherwise, it can go until you get tired of looking at the light or have extra cash to get it fixed.
Chances are the sensor is just bad and nothing's really wrong.