** it's high mountains, so temperature changes are frequent. You should bring a lot of light layers you can carry with you or not, depending on temps on the day, and take on or off during the day. It can vary from really broiling hot to quite cold (almost freezing)
** water is an issue. Make sure you have a Camelback or similar system. There are ones designed specifically for ultra-runners that are ultra-light. I think www.racingtheplanet.com has some for sale, and "Runner's World" frequently reviews them.
** rain gear is important -- I brought only light rain gear, and was worried when I heard stories of past freezing torrents, but lucked out because our race ended up being sunny. I have heard good things from friends who own the Ultralite Goretex rain suit made for runners. Again, the mags have reviews.
** things I brought and didn't need: extra food for other than race times (what the tour includes was plenty and good -- if you have special favorites you could bring them but not necessary), lots of reading material (some was good, but I found I was a lot more interested in just walking around -- it's SOOO beautiful up there!)
** things I was glad I brought: a good notebook, a sketchbook, plenty of sock changes, trail-running shoes with decent support, Camelback, and plenty of race-time supplements (I use those "Gu" tubes, not tasty but hit the spot at about 30K, and I brought enough to be able to share with some fellow runners who were flagging, which I felt good about)
** things I wish I'd brought: a better camera, better rain gear as above just in case, good pants for riding (excellent horseback riding is among the options for free time)
** I saw lots of families there and the kids all seemed to have a grand time. Just make sure they pack whatever they need for entertainment. There is fishing and boating and hiking and biking & horseback riding & etc. They should probably bring their own boating safety vests as I'm not sure I'd vouch for the kid-sized ones the camp provides. Also, if your husband fishes, he may want his own tackle.