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?

You may want to refer to this article on this topic: https://vulcanpost.com/203731/short-term-rental-new-life-jaded-hotel-industry/ I think if you have a HDB unit, it is not legal to rent out the room on a short-term basis (less than 6 months). Not so sure if the rule extends to private apartments (though I think the same rule is advised by URA). Personally, I would not take my chances since the consequence may be losing the unit. Better to consider renting it out for at least 6 months. That way, you can still earn from the rental if that is an option you are considering.

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.