I loved flying into Sanford!! It's a wonderful, user-friendly airport. I have been picked up by a car service there, but find that getting a rental car is the best way to go. The drive to WDW is very straightforward and easy. Takes about 50 mins.
The car rental counters are just past the baggage claim area. In fact, the last time we flew into Sanford, I headed directly to the car rental counter, while everyone else got their bags. I watched them get their bags and head over to the rental area. I was just finishing up my paperwork when they arrived. We walked out the door, crossed the street and got into our car and drove away....took less than 30 mins after landing!!!