I have braces too and it isn't really that bad except when they tighten them after you get used to it.
They'll take casts of your jaw to work out what size and shape of braces they'll need, the stuff tastes awful but it doesn't hurt. Then a few weeks later when the results are back they put on the braces.
First the dentist cleans and polishes all your teeth. Then he'll blow air over the tooth he's about to put a bracket on. They put glue on the bracket and put it on the tooth and you have to hold your mouth open while it dries. Usually around your second molar (second from back if you've got your twelve-year-old molars) they have to put on a band that goes all the way around the tooth, and that hurts a bit, but not for very long. The modern braces often dont' need that, they put on a different type of thing that only goes on the front, but my teeth were really bad so I had the worse sort. He'll put a bracket on each tooth but usually not the twelve-year-old molars.
When they're all dry, he'll thread a wire through the brackets. It's called rebound wire and it 'wants' to return to its original shape - in this case, the optimum shape for your teeth as determined by the casts. They get gradually stronger (changed about once a month) to pull your teeth into line. To hold the wire in, they put little rubber bands called ligatures on the brackets, these are the coloured bits you can choose to have on your braces. Sometimes if your teeth are gappy, these will be joined together to pull your teeth closer together. Those hurt, I have them.
Because they put pressure on your teeth they hurt for a few days after you get them put on or tightened, but apart from the nuisance of not being able to have soft drink or anything really sweet, and the pain when they crank them up, they aren't that bad.