It has been at least 7000 miles since your last oil change OR they did not reset your maintenance light at the last change. Here is what you need to do if you are not due for an oil change:
With the engine off depress and hold down the trip odometer reset button. Start the car and hold the button off for ten seconds (until the maintenance light stops flashing). Release the button. Turn off the engine.
Next time you start the car the light will no longer flash. This procedure must be done at EVERY oil change. Incidentally, the light will come on and stay on solid (no flashing) once you hit 7500 miles. By now it may already be on. The procedure for turning it off when it is solid is the same.