Chiming in as one who’s had the same procedure for the same reason. I, too, had a deviated septum that prevented proper breathing (when my ENT asked “how on earth do you breathe?!”, I replied, “through my mouth, is there any other way?”), and, like you, as long as I was going under the knife, I wanted some minor cosmetic changes as well (actually, they were somewhat necessary, as my septum didn’t end in the center, but was bent off to one side, making one nostril rather thin compared to the other).
However, this was my big mistake… though the diagnosis and prescribed treatment came from two ENTs, since I wanted cosmetic work done, too, I chose to have the procedure done by a cosmetic surgeon. I did a lot of research and found one of the best in the state, and, I must admit I have a really great-looking nose… that still doesn’t work, however. 
Granted, I don’t suffer the debilitating sinus infections I used to get, but I still can’t breathe properly, either. And now I can actually feel the deviation near the top of one of my nostrils, even though it’s unnoticible to the eye.
I’m told that it’s probably not the septum, but a problem with my turbinates, which should’ve been addressed at the time of my surgery, but wasn’t because my ENT didn’t specifically mention them as a problem.
So, after all that, here’s my advice: seek out an otolaryngologist, or otorhinolaryngologist, that also does cosmetic work (sometime after my surgery, my ENT group brought in a partner with specialties in both fields <sigh>) and make sure to ask them to examine your turbinates to see if they need any work while they’re already in there.
As for after-effects, as others have said, expect some minor bruising and a little pain and/or discomfort. Ice packs and pain meds help. I was up and around and feeling great in just a couple of days. And yes, it is utterly amazing how long those splint thingies are and that all of that could be stuffed up your nose!
Oh, one unusual thing I noticed, though, is that I’ve never had so many people accidentally (or purposefully!) bump/hit my nose so much in my entire life as I did within the six months after my surgery. :eek:
Good luck and let us know how it goes!
(P.S. If you want to see some before and after pictures of mine, you can do so here.)