when you're doing hours on the road it's definitely essential to hydrate as you go, not stop and pound a water bottle. that'll probably make you piss and probably waste more water than really hydrate. it's also important to get hydrated before the trip, it takes a day or something to really get your body hydrated.
lots of people are put off by gatorade and such these days because of high sugar content.. i don't really care, i still drink them, but some people recommend pedialyte instead. You can also get drops that you add to water that give it a little flavor and electrolytes. or chuck a lemon or something something in your camelback. (also ice!).
I've used camelbacks when on the road.. it's nice to have a backpack you can stash some stuff in and if you go walking around you can keep it with you, remember to re-fill it etc. You want one with a magnet to hold the valve in place so it's not blowing around or rubbing on you. Also a 90 degree bite valve helps you get it between your chin bar and face. That said, if you don't have a tank bag you should get one and they often have hydration pack pockets... it lets you have easy access to stuff and you you don't have to take your backpack off. Also less weight on your back the better, although people really rave about the kriega backpacks, i haven't been able to use one yet. i always keep my phone, wallet, snacks, extra drinks, some tools, bungies, zipties, sunglasses/hat, visor/visor cleaner/rag etc. in my tank bag. stuff that you'll need quick access to when you stop for directions/bathroom/food.
oh! and post it notes. i'm not good with using maps because they don't quite have the detail you need, but if you have issues with your navigation and directions you can take a sharpie and write directions on post it notes in the map pocket of your tank bag (so they don't blow away or get wet). I use arrows and the road name, if you have time, include mileage on said road. so like:
<- Oak St 3.2 mi
-> walnut st 5.8
It's also a good idea to download some offline version of a map because you won't have cell service everywhere.