yup! hiked pretty much all of arizona - sagurao NP, sedona, flagstaff, coconino NF, the san fran peaks, mt elden, mt humphreys, the north rim and south rim of the canyon.
havent done much in utah other than southern Utah. i helped build the arizona trail which actually goes into utah, so i've done parts of that
do you know what area specifically you'll be doing on the North Rim? i've backpacked a little bit there. if you're by chance doing Havasupai Falls, i've done that. awsome little trip.
know that northern arizona is not like southern arizona. it can get damn cold, even this time of year. so make sure you bring plenty of fleece and capeline/long underwear. you'll need it most likely. especially if your descending into the canyon.
but of course the sun in that area can be pretty brutal so obviously, you'll want clothes to match the hot weater and lots of sunscreen . but of course!
also, Northern AZ has a monsoon season, which usually starts mid july - mid august. so if you're there during that time, you'll see some kick ass rain storms, but tey only last for literally, a little more than an hour and then everthing is bright and sunny and happy. but it's some hardcore rain!
sedona - usually 20 degrees warmer than the flagstaff and grand canyon area. so be prepared for that.
southern utah is pretty open...you'd be suprised how many trees/forests there are in N. arizona, but s. utah is somewhat barren (not really the right word!) so therefore, warmer - more like the sedona climate.
will you be backpacking or just day hiking?
either way, bring extra water, of course.
as for zion and bryce...it'll get pretty cold at night like the canyon area, so be aware of that.
if you do spend time in the flagstaff area, and have extra time, check out Mt elden (the sunset/north trail is much prettier than the south one), mt humphreys (you need a whole day for that - it's the tallest peak in AZ, at about 12,900 or so). there's an awsome hike about thirty minutes south of the canyon called red mountain. freakin awsome.
sedona - if you don't dig lame tourists like me
you'll want to check out the more backcountry trails, obviously. there are annoying jeep tours that for some reason have not been outlawed and they can be really damn annoying. so again, if you want to avoid them go further out. there are some cool arches around sedona that have good hikes to them.
awsome climbing in the sedona area also!