Please excuse the ping out of nowhere. When I went through this with my mother, the best things to bring are things to read and if you do any crafting, see if you can bring a project along. DON'T bring anything like your laptop or your 3DS or anything like that.
Get used to sponge baths from the sink until those staples or stitches come out. They're tricky and no, you won't feel clean but you won't be filthy. Get one of those hair washing stands if you can, borrow it if you must. Oh, and the toilet? Say a prayer, five Hail Marys and aim. Don't drop down. You'll do yourself more harm that way than any other way.
Unless it's something really serious, I, tbph, don't see why you'd be in the hospital for more than three days. Mom had her knee completely replaced and she was in and out of the hospital in three days.
Anyways, best of luck with it. c:

Ear plugs and sleeping mask! If you're sharing a room with people, you're very likely to get someone who snores / plays with their super-luminescent phone all night.
Otherwise, what to bring depends on where you'll be staying. With all my resident surgeries, I was lucky enough to stay in small rooms with only one other person (and once I even had a room to myself), where bringing slightly more precious things was fine, because the amount of people coming and going was very limited. A couple of the rooms I stayed in also had safes (those little ones you get in hotels), so I could put all my money etc. in there and not worry about it. I had friends and family around, though, who could get stuff for me or put it away again.
Give the hospital a call in advance and ask, you should have a contact number on your surgery information sheet (or similar). If you're going to be in a six person room, don't take anything you can't keep in your sights (or under your pillow). There might be a TV (or several) in your room or on your bed, or there might not be - there's really no way to know without knowing the hospital.
As to nurse duties, if you're completely bed-ridden, they'll do everything for you: meds, drinks, food, washing, bathroom, dress/undress, all bells and whistles. There'll be a call button for you to press if you need anything. Don't feel guilty about pressing it at night, they're up anyway and they'd much rather you called about going to the toilet than you ending up wetting the bed. You might be able to get up and go to the toilet with help, in which case they'll help you walk there. Depending on how fuzzy you are, they might close the door or not, so it's entirely possible you might have to pee with someone close by. If you can't move at all, they'll either lay a catheter (which is unpleasant but manageable), which will just result in you peeing into a bag, or they'll bring a mobile receptacle for you to pee into. None of these things are pleasant on an emotional level, so just keep reminding yourself that all care staff have dealt with a lot worse and aren't judging you for the fact that you need to pee.
General advice: Be very lovely to the nurses, because they do all your hands-on stuff. Ask all the questions you have when you have them, regardless how rushed off their feet people seem - it'll worry you a lot more in the long run if you don't, and lots of nursing staff are underpaid and overworked and have to move at speed to get all their work done in a day, so it's very possible they'll forget to mention something.
Good luck!