Driving in Bali isn't the huge task it might seem on arrival. There are plenty of places to rent a car cheaply and quickly and the driving isn't too challenging.
Driving as a tourist. Tourists often comment that the roads in Bali seem a madhouse, and this frightens people away from driving. Most local people in Bali have never had a driving lesson. They don't need to, as you can get your driving license without taking a test (but its cheaper if they take the test). The road skills people have are earned by plugging headfirst into traffic, and muscling their way through, like everyone else is doing. This can be a hard concept to learn, putting the western idea of 'road rules' aside, and taking up a 'law of the jungle' approach, but that's how it is.
Driving styles. Balinese / Indonesian drivers do things a little differently at intersections. Whereas in the west, we are taught to wait our turn, pull into the middle of the intersection and execute a turn, over here many people cut across to the oncoming lane, going head on to traffic, before switching lanes at an opportune moment. They think this is a smart and sensible way to drive, as it saves a few seconds. The problem with this is puts you in a head-on situation, and forces you to cut across traffic in the lane you are trying to get back into. This tactic is used mostly by motorbikes, but if you are a tourist and plan to rent a car, it's good to know what to expect...