I got my car painted last spring, and urethane clear coat. What's good to put on the car to protect it? A specific kind of wax? Glaze? What works well with this kind of clear coat?

This is one of those things where everyone has their own way of doing it. It all depends on how far you want to go and how much time you want to put into it.

New school guys use paint sealers that can last up to a year or so and old school guys live and die by carnuba wax that lasts 3-6 months.

Get the car as clean as possible with a wash and clay bar or cleaner wax. Then buy your favorite wax (Meguiars and Mothers are considered the best by most people who don't want to spend a fortune) and put on 2-3 light coats. I don't recommend using a clay bar on a dark color unless you don't mind polishing out possible scratches afterward.

Then after that just make sure you don't use any abraisive cleaners or dish soap to wash your car. They can wash the wax away and leave your paint unprotected.

Buying a cheap random orbital polisher and some nice micro fiber towels makes the job a whole lot easier. If you are going to buy a random orbital, don't go for the cheap looking ones you see at wal mart that are shaped weird.

I use this Makita

http://tinyurl.com/28kdksm

Dewalt and other companies make other similar ones but I like how the Makita is smaller and hand held. Go to a paint detailing shop or site online and find a wax pad that has a hook and loop backing so it'll stick to the polisher. It can be bigger than 5" because you're just applying wax and you aren't going to catch any corners and burn the paint anywhere.