There are both buses and colectivos running between the bus terminal and the city center, but the service is relatively infrequent and stops around 9pm. During rush hours the bus trip between the terminal and the city center may take up to an hour.
From the center, take the northbound colectivo marked 'Terminal' from Carrera 10 anywhere between Calles 19 and 26. You can also take a bus or colectivo from Calle 13 west of Av Caracas.
The best and fastest way is a taxi (US$4). The same applies if you are going from the terminal to the city center; you can take a bus or colectivo, but it's best to go by taxi.
The bus terminal has a similar taxi service to the one that is at the airport. Upon arrival, follow the 'Taxi' signs, which will lead you to a taxi booth where you'll get a computer printout indicating the expected fare to your destination.
TransMilenio apart, Bogotá's public transport is operated by buses and busetas. They all run the length and breadth of the city, usually at full speed if traffic allows.
Except on a few streets, there are no bus stops - you just wave down the bus or buseta wherever you happen to be. You board via the front door, pay the driver or the assistant but you don't get a ticket. In buses you get off through the back door, where there's a bell to ring to let the driver know to stop. In busetas there's usually only a front door through which all passengers get on and off. When you want to get off tell the driver 'por acá, por favor' (here, please) or 'la esquina, por favor' (on the corner, please).
Each bus and buseta displays a board on the windscreen indicating the route and number. For locals they are easily recognizable from a distance, but for newcomers it can be difficult to decipher the route description quickly enough to wave down the right bus. It will probably take you several days to learn to recognize busetas and buses.
Fares range from US$0.30 to US$0.50 depending on the class and generation of the vehicle, and are slightly higher at night (after 8pm) and on Sunday and holidays. The fare is always posted by the door or on the windscreen. The fare is flat, so you will be charged the same to go one block as to go right across the city.
There are also minibuses called colectivos, which operate on major routes. They are faster and cost about US$0.50.
Bogotá has an impressive fleet of Korean-made yellow cabs. They all have meters and drivers usually use them, though occasionally the sight of a gringo can make them reluctant to do so. Insist on having the meter running or take another taxi. Taxis also should have stickers displaying day and nighttime fares.
Taxis are a convenient and inexpensive means of getting around. A 10km ride (eg from Plaza de Bolívar to Calle 100 in northern Bogotá) shouldn't cost more than US$4. There's a US$1.25 surcharge on rides to the airport.
You can either wave down a taxi on the street or request one by phone from numerous companies that provide radio service, eg Taxis Libres (311 1111), Taxi Express (411 1111), Radio Taxi (288 8888) or Taxi Real (333 3333). They all have a fixed sobrecargo of about US$0.40 for this service, and will usually arrive at the requested address within 15 minutes (this may take longer on weekend nights).
A word of warning: when taxiing from the bus terminal or the airport to a budget hotel, be wary of any driver who insists that your chosen hotel no longer exists, has burned down or suffered some other inglorious fate. They may be trying to steer you to a hotel that pays them a commission.
Bogotá has one of the world's most extensive bike-route networks, with over 300km of bike paths. Most paths, however, are in the north, and central areas still suffer from heavy traffic. If you have a bike, the best day to go for a spin is traffic-free Sunday.