Map's Verses GPS is the nub of the question. Also learning a skill of map reading is not a skill to be sneezed at. I've done a lot of travelling and map's on a whole are I find are more or less the same. It's the scale of map you are going to use. The larger scale is going to give you bigger cover and a smaller map to carry. I find an A4 size map book is a good size to play with. As what usually happens is you plan your route the night before. Then write the road number's out and distance's between each junction. A GPS is a good thing to have to get you from your over night stop on to the road you need to be on, to start your journey. And if you see something off the beaten track. You can go and explore and the GPS will bring you back to where you need to be to carry on your journey.
Each one is good to be used with-in it's own limitation's.
To buy petrol in Europe. Pull up at station. Wait. Get out a 20 Euro note, then ask someone to fill up the bike. Give person money. Ride away. Simple.