I want to decorate some tiles for a local hospital.
What materials will I need?
Tile, paint (what sort of paint), kiln (?), ?
Sorry - I’m a bit clueless when it comes to art.
Paint is not what you need. Clay tiles are glazed, not painted. Glazing is a process of fusing a slurry of pigmented glass to a clay body via intense heat (I’m simplifying). It isn’t really a thing to think of doing casually on your own, especially if you are starting from what appears to be complete ignorance.
Get a book out of the library, take a community college or adult ed class. It isn’t something to learn how to do from the internet, seriously.
I don’t have time for reading books or attending classes.
You can get tiles that are unglazed and the paints to use at an art store. But you’ll still need a kiln to glaze them. I remember at one time some kind of technique for doing it without a kiln, but I don’t think you get a durable tile like surface out of it.
Since I didn’t remember any details about this, I searched on “how to make your own decorative tiles” and plenty of info popped up.
Around here there are lots of places (like this) that have “green” ceramics and all the materials to decorate, glaze and fire them. I’d look for one of them near you.
Are they going to be floor tiles or just decorative wall tiles? I think floor tiles need to be much more durable, which you’ll probably need a kiln for. If you’re just making decorative wall tiles like https://lh3.googleusercontent.com/-JB98F9TVa4M/S-5Zzk7OHZI/AAAAAAAADiU/nVXjo5Otx70/s800/PMBS1095.JPG (although I think these were fired, because they were in a ceramics museum), you might be able to use oven baked clay from arts stores.
They will be decorative wall tiles.
Does glaze have to be used on ceramic (not clay) tiles? What about ceiling tiles?
You can get plain white glazed tiles and paint them with various materials that set in the ordinary oven - I’ve used Porcelaine before, it’s quite good. Only downside is you can’t use it for plates you want to eat off (the actual eating surface, I mean), but otherwise it’s exactly the thing for you. You could also probably have some success with the stained glass products like Vitrea, but those are transparent glazes.
Get creative with wall murals, stickers, decals.. Easy, nice, cheap, and removable if you or they don’t like it.
You can also buy a bunch of old colorful tiles, break them into pieces, and glue them to the tile wall, then grout it. Quite easy for an amateur, not that expensive either. Here are some images of finished tile mosaik. My brother made a tile backsplash for his kitchen that way, very nice. Tile mosaiks go easily over another tile wall.