If you're needing to travel just about anywhere in Bandung, the Angkot system (little multi-colored buses) is fabulous, as long as you're aware of a couple of things. One is that most of them stop running shortly after dark (6pm-ish), so plan accordingly. Another thing is that although. While a number of friends have encountered pickpockets in Jakarta, with none so far in Bandung, it's not a great idea to be foolish: keep track of your stuff! Most trips will be between 2,000 IDR and 4,000 IDR (in late 2014 about .17 and .33 USD), some longer trips could run a bit more. Try to have small bills and coins on hand - the driver will not be happy at having to make change for a 50,000 or 100,000 iDR bill.
One of the problems with using the Angkots is figuring out which one is right for you. They will have a beginning and ending destination posted, typically on the front window, but that won't tell you the route taken: quite a few go from Ledeng to somewhere else, for instance. There are apps and websites that can help you with this. The word used for having the driver pull over to let you off is "Kiri", and if you search for that term and "angkot" you should find useful information.
Having figured out which one to catch and where, you simply indicate that you want to ride with an upraised hand or nod, get on (they do get crowded at peak times), let the driver know where you want to go (PVJ (pronounced pay-fey-jeh), Istana Plaza, Trans Studio Mall, BIP (pronounced bay-ee-pay), etc.) and they'll typically help you know when to dismount. Anytime you want to get off, just say "kiri" (kee-ree), which means "left", and the driver will pull to the left as soon as possible. People ride with bigger items they've bought, but the angkots are more suited for people traveling light. Don't try to ride with a bunch of big suitcases - a seasoned traveler's backpack will work just fine. One other caution to mention: many of the angkots have alternate routes (Ciumbuleuit Belok and Cuimuleuit Lurus, for instance - this means "turning" or "straight") and you may want to check with the driver that it's going where you expect.
The price of the travel and the friendliness of the people is a powerful reason to enjoy this adventure, and you probably will, especially if you're armed with this secret weapon!