At first you'll be very conscious of them but after a month or so people will get used to seeing you with them and you know you're going to have a lovely set of teeth at the end of it. My orthodontist advised using the wax from ear plugs (remove the cotton wool first!!) as this is so soft and creates a cushion to pretect friction against the inside of your mouth, soften it between your fingers before applying. I used more at night and only put it on bits that rubbed during the day.
As sara3 says; make sure there are no wires pricking into the inside of your mouth before leaving as it's such a pain to keep going back, however, as I say the ear plug wax is good for this if it the wire did move.
I don't know if you're having a transparent brace or the metal one but if it's the transparent one be careful of what you eat and drink. I stopped strong tea, no coffee, no red wine, no curries etc but was caught out with some blackcurrant sorbet at a restaurant so the brace was purple for a couple of weeks!!
Good luck, you won't regret it.