Malaysia's food scene is a mixture of traditional Malay food, Chinese, Indian, Nyonya and some fusion. Just like in Vietnam, a lot of locals eat out regularly, so the food scene is huge and there's no need to use tourist restaurants (like you might find on TripAdvisor).
This guide has some food from each of the cuisines but I definitely favour the Indian-style dishes. Food in Malaysia is very cheap and isn't exactly healthy. There is a bit of an issue with sugar here - the locals love it so much that they have problems with obesity and diabetes. The first step to avoiding the crazy levels of sugar is to learn how to ask for your drink to come without it. I always order the very cheap "teh o ais kosong" (teh = tea, o = no milk, ais = ice, kosong = no sugar).
In most restaurants, someone will come to ask for your drink order once you've sat down. If it's a shared area with many stalls then you need to pay the drinks person separately when the drink arrives, otherwise it is usually paid together with the food at the till at the end.