Crohnzie girl, heres a link to a thread about what to take to hospital
http://www.crohnsforum.com/showthread.php?t=42611
There is also a forum wiki that gives suggestions - there are a few pages here:
http://www.crohnsforum.com/wiki/Hospital-stay-what-to-take-non-urgent-help
also these ones which I haven't read but am sure ma have some helpful hints:
http://www.crohnsforum.com/showthread.php?t=18214
http://www.crohnsforum.com/showthread.php?t=47819
As to post surgery the main thing is to get up and moving as soon as possible. Make use of the pain meds to make yourself mobile. It really makes healing faster and gets everything working again so that you don't have as bad gas pains etc. Obviously you need to take the advice of your surgeon and the nurses first but I know from experience that recovery is a lot easier when you are able to get mobile. My last op the pain relief was not adequate and so I was unable to get moving and I swear It took much longer to get over it all. Of course I was a little older and in worse condition so maybe that had an effect too.
Start eating when the surgeon advises but don't force yourself to eat more than you feel like. Your body knows what it needs. Protein drinks are great because they are easy to get down and are good for healing.
If you have any worries about infection etc like Jenn said follow up on it. Again after my last op, I kept telling them there was an infection under the wound but they said no it was fine and sent me for X-rays etc to see what was causing the temperature - sure enough 5 days later the wound burst open. We know our own bodies and what is normal.
Other than all that try and relax, take lots to keep yourself entertained and if you are in a general ward don't forget the earplugs!!!!!! and a sense of humour.
And most importantly if you treat the nurses with respect and an understanding of the demands they have on their time they will pay you back threefold. I used to find grouchy nurses very upsetting, one could ruin my day, then I decided I would try and win them over. Hey presto, no more grouchy nurses and no more emotional days for me.
(well there was still this one B) but thats another story.