One of the best ways to see a place is by bicycle. You can rent a bicycle at one of the many shops that costs only a couple of yuans per day. If you want to go beyond the city borders beware of the big roads. Pollution is extreme and road conditions are very bad, so accidents are quite usual.
Boat trips are probably the nicest way of travelling through China. The most important route is on the Chang Jiang (Yangtze) between Shanghai and Chung Qing. For travelers coming from Hong Kong and travelling through Guangzhou (Canton) to Guilin, there is a combined ticket of boat and bus.
There are two main type of buses: city buses and overland buses. Both run frequently and are very cheap. Since these buses are extremely crowded, you have to be very careful of pickpockets. The bus net is very extensive and the fares are quite low.
With over 52,800km of tracks, the train is one of Chinas main means of transportation. However, most of these tracks operate with diesel or coal, only 5,700km are electrified. A good way to spend time on the train is to go to the dining car. Meals are usually cheap. Trains are usually very punctual and safe. Tickets are sometimes quite limited, so the best thing is to book your ticket in advance.
It is best to take taxis that are licensed and metered. If not, agree on the fare before the driver starts the journey.