Anything that doesn't move and doesn't explode is legal. Basically, the only legal fireworks are sparklers and fountains.
Rockets of any kind, firecrackers, ground bloom flowers, roman candles, etc. are all illegal. It's relatively loosely enforced though, unless you're doing stupid shit or pissing off your neighbors. Keep it inside your yard or on your driveway and clean up after yourself, and you'll be fine.