There are loads of guides offering services to guide you around the island.
I got one for RMB 20 for half a day (i arrived in the afternoon and was a bit short on time), so I told the guide I wanted to only visit 3 attractions in the afternoon.
Note: When you get the guide, you will need to register at a "tourism counter" near the ferry terminal. You pay directly at the counter.
1. The guide will provide heaps of information on each of the sites visited (although I don't remember 99% of the things she said).
2. If you're short on time, the guide can find you 'short cuts' to your destination, walking along small alleys.
The normal practice is that the guide will take you "Shopping" in between the stops. This way they earn a bit of commission from the shops.
I had to use the "time" pressure to get around this, as shopping wasn't on top of my list.
Most attractions closed around 4:30 - 5:30 pm (Dec 08).