Find the closest airports to your beginning and ending points. Pick the car up and return it to these places. You can waste a lot of time by asking non-airport rent-a-car locations whether or not they do one way car rentals. A few of them do, but not many. Almost all major airports do.
If you plan to book your car rental online, use a service like Orbitz instead of a service like Priceline. Priceline doesn't deal with one way car rentals, while Orbitz makes it easy by asking for the pickup and the drop off locations.
Always make sure that the amount of mileage that is included in your rental agreement will be enough for you to do everything that you need to do and still get the car to the drop off point. It's usually best to opt for the unlimited mileage car rental deals.
