I'd say if you're planning to stay in hospital for more than a day or 2 it's probably best to pack a bag for the first couple of days & another for the second half of your stay that can be brought to you when needed. They don't usually have a huge amount of storage space next to the beds & can get a bit funny about you having more stuff than will fit in one little cabinet. Don't forget to pack a second bag for the baby too & make sure your DP or someone knows where to find anything else you might need.
Another thing I'd say for anyone going into hospital is to make sure you're told where everything is & ask if you forget. With both my DC I was shown to my bed & left to it. Eventually I discovered where the loos were, that there was a day room with a fridge/microwave I could use, that I could put expressed milk in said fridge if I labelled it... I was expected to change the cot sheets if they threw up on them but no-one told me where to get fresh ones from. They're usually v busy on postnatal wards & it's way too easy to be overlooked if you don't demand attention!
Also, if the Bounty rep comes round you're under no obligation to give them any personal details. Despite what some of them say, you don't need their pack to be able to claim child benefit - the packs do contain the form but it's not the only way to get a form. If you give them your details you tend to get a lot of junk mail for a while after.
Oh, & if my experiences are anything to go by, don't expect to get any sleep - there's always at least one mum on the ward who sleeps through her baby's crying & just when the baby gives up & falls asleep the mum will wake up & start making weird cooing orgasm type noises at the baby.
One last thing... You're perfectly within your rights to discharge yourself if there's no suspected health issues with either you or the baby & you feel you'd recover better in calmer, more familiar surroundings!