There are numerous angkots around the city, so once you reach a main street its easy to find one, but the problem for a foreigner (and maybe even for some nationals) is knowing the right angkot to take. The angkots run different routes through the city and usually have terminals where they start and stop. Thankfully the angkots are color coordinated and state the terminals they run to and from. I've only got a few of them down so far, but have enough language that I can usually get to the place I'm going by asking the drivers or the many friendly Indonesians. If one's destination is far, they'll usually have to ride a few different angkots.
Sometimes a person may ride alone or with a few others, but the drivers seem to like to get the most people possible inside an angkot. Therefore, they can be quite crowded with two people in the front seat with the driver and maybe up to 12 on the bench seats in the back lining the sides of the angkot (children excluded because they can sit on laps). If you want to get out, simply say "kiri" ("left" or in this case "pull over") and the driver pulls over, or if getting on, raise your hand at the next angkot. The driver's desire to fill the angkot often becomes the frustration of those riding because the driver will sometimes pull over and wait for people to come on for several minutes before going again. Thus, a second form of public transportation is the ojek, motorcyle with driver - quicker, usually for short distances. Taxis are also available. The angkot is certainly the cheapest with the price running about $.20/mile. In perspective, a good meal can be purchased for about $1.
Here's some photos of a few different angkots and some shots from the inside of a full angkot.
