Hey Lana, I used them to cover up a really ugly ceiling a couple of years ago and I loved working with them. They're so light and easy!
Do make sure they they are accepted by Landlord if you live in Rented before installing them. Some (in UK) are not acceptable as considered a hazard(Toxic smoke when they melt ) if you have a fire in the building. Best wishes.
If you wish to paint them, dust and vacuum them first, if they are sturdy enough. Then roller paint them with a water-based paint. Clean the grid they fit into also. Best wishes!
I've seen a great video here on "Home", and have seen them on google. Easy to put up I think.