Dutchmen had some great advice.
I especially like the tip about starting to look for gas options when you are at 1/2 tank. In my experience, truck stops right off the interstate are the easiest, even for gas. They are usually somewhat new and were built to accommodate many vehicles. They also usually have several ways to get in and out.
I have also had to to do the small town gas station thing while hitched up, and that usually required a spotter.
I was very nervous at first about fueling while towing, but it's really no big deal, IMO.