Hopefully everything will go smoothly for your adventure - sounds like fun!! Besides what has already been mentioned I would consider getting one of those multi-bike tools for your pack. When we were riding last weekend, one of my brake pads started an awful screeching sound whenever I would apply the brake, so DH pulled out his allen wrench on the tool set and removed the brake pad - it had picked up a small piece of metal and he was able to remove it. He has used it numerous times to adjust our bike lights, brakes, cables, etc. Very handy item. We also carry a small bottle of chain lubricant. And a small first aid kit - hope you NEVER have to use that, but I actually made fun of DH when he insisted I put one in my bike kit and sure enough, I had a fall the following weekend and got road rash on my elbow - the first aid kit has Neosporin, a number of bandaids and some Benedryl cream (for bug bites). We used one of those tiny little digital camera zip up cases for the first aid kit - very lightweight. Have fun and I wish I was riding with you! Have you started a cycling diary/journal yet? I like to put a brief description of each ride and what I saw along the way and it is also a good way to keep track of mileage, etc. We also pack a small digital camera too. We brake for wildlife/scenery! Enjoy!!
“No Bird Soars Too High If He Soars With His Own Wings” ~ William Blake