Congratulations and Good Luck!!!
One thing to do to get through the next 2 weeks is make a list of all the things you're going to be able to do or free of once this is all over that you can't do (or have to do) right now (don't forget to put down no more colonoscopies!!!). It will be a positive reinforcer of why you are doing this and can also be used to set goals. A big one for me was getting to be drug free and losing the effects of the drugs and the disease.
Another thing to do is find out how your insurance wants you to get your ostomy supplies (some have preferences), what they cover, etc. It's easier to get that information over the next 2 weeks than when you're on pain meds and recovering. You will want to make sure that you take home enough supplies from the hospital to last for at least 2 weeks when you get out of the hospital. Don't let them send you home with just a couple of changes as you can go through that in a day as you're learning the best way for you to change.
Make sure that you have a place that you can sit when you shower at home even if it's just a plastic outdoor chair in the tub and use it. If you are going to be staying at a hotel at all immediately after surgery, make sure you get a handicapped room. Lifting my legs over the tub was exhausting for me after surgery #2, even though I was healthy going into it, because of the loss of my abdominal muscles and general weakness following surgery. I would also recommend picking up a changing pad (in the baby section - usually carried in a diaper bag). I slept on mine and it caught more than a few middle of the night leaks/blowouts. Thanks to summerstorm for this recommendation. It saved my sheets and mattress more than once.
Hopefully they told you already, but be prepared for all the tubes. The first surgery there won't be many. One thing that they told me after surgery that I wish I had known before (and they may have told me but I forgot), was that even though mine was hand assisted lapro, they cut my ab muscles vertically. If I'd thought about an open surgery scar I would have realized this but on all the drugs and wrapping my head around everything associated with surgery, I didn't think about it. This helps the pain and movements you can and can't make post-surgery more logical (ie - don't sit straight up in bed - roll on your side and push up with your arms).
Here's my list of essentials that I used for my surgeries - hopefully it can help you. TP (the hotel had really scratchy TP that hurt after the dry air of the hospital), heating pad (for the hotel room as I always had back pain after surgery because of my bad habit of slouching which is not recommended), standard bathroom stuff - hairbrush, toothbrush, preferred shampoo/conditioner if you have one, etc., socks, slippers (mine had grip so I used them to walk), comfy pants (elastic waist) to wear home, loose top(s), warm socks, old underwear (in case of leakage/blowout I could throw them out instead of packing them to bring home), books, face wipes (to clean my face when it felt grimy), lotion (if you have a preferred one), lip gloss, and chargers for everything electronic, a pillow to hold against your abdomen when you laugh or cough while on your way home (also useful to put between you and the seatbelt for the ride home). I'm not sure if you're male or female, but if female - be prepared for your monthly visitor whether it's the right time or not. I always brought my camera, MP3 player loaded with soothing music along with amp up tunes for when I needed motivation, cell phones, and computer.
I agree with Blueheron on the writing/documenting the experience. I started a blog after my second surgery to keep track of how I felt and how things went, changes that occurred day by day, etc. I wish I had started it sooner as I know that some details are really fuzzy a year later (not that they weren't fuzzy from all the drugs then - but it's only gotten worse as time has passed). It also allowed me to look back and see how far I'd come, which was very useful on bad days. You might want to start keeping track now of the experience if you aren't already. It's nice to be able to look back on it a year later and remember how sick I was and how having these surgeries truly did save my life.
If you haven't yet, check out jpouch.net and go through Mark and Megan's documentation of Mark's surgical experience if you're comfortable with the info. This allows you to see what your stoma will look like, what the bags will be like in the hospital (fyi - you don't need to keep the clear ones - or the big ones after you get out of the hospital) and what Mark's experience with surgery was like.