Is renting my home or rooms on websites like airbnb or easyrooms a good way of makingside income? Are there any legal repercussions with doing this in Singapore?

Better not to, some governments around the world are clamping down on AirB&B rentals. If you have a free room, why not rent it out long-term but for short periods at a time. For example, there are always exchange students studying in Singapore for a few months (usually 6) at a time and you can rent rooms to them for a semester and make some quick money from it.