take along some passport pictures too...seem to recall that we needed to have photos for the entrance ticket; we also got the 3-day pass, and after a while, it got tiring seeing all the temples but of course, while you're there, you'd want to make the most of it.
if you do head for the sunset view, try not to stay too long as you need some light to trek down. I agree with uncertain traveller that it does get rather tricky to go down, and luckily for us, we decided to head back before the whole crowd headed down, and that there was still some sunlight to lead us downhill.
bring a lot of small dollar bills as the US$ was the currency we used and watch out for the many vendors trying to sell you a souvenir. when you reach a spot by the temples, watch for that imaginary line ...there's a rope on the floor that if you pass that line, the vendors will crowd to you but once u get behind the rope line, seems to be an unwritten rule that the vendors cannot go beyond this line.
the airport is near the town area so it is actually easy to move around and do your own tour as it is so easy to hire a car and driver at the airport or at your hotel. we stayed at a bed & breakfast for $25/night years back, and airport transfer was only US$5 and we rented a mini van for about $25/day inclusive of a driver which was all handled by our host. Make sure your vehicle has a strong air-conditioner as it can get really hot and humid!