Best advice I (or anyone else) can give is: Do an over-night test run before going anywhere. You will have to figure everything out on your own.
I would put my sleeping bag on the top of the rear rack in a waterproof stuff sack, never been a problem. I can't imagine putting it in a pannier, that's just me. Make sure you have all the extremely annoying rattles and clunking noises dealt with before hitting the road. Make shure chit doesn't end up in your spokes. Be flexible, this is supposed to be a relaxing time.
Where are you going and why? Is this a pedaling focused tour? Are you looking for cityscapes? When touring, I prefer riding a lot in a natural and secluded setting, this dictates almost everything else.