Originally, the section through the French Alps from North to South was know as the Grande Traverse des Alpes and runs from Lake Geneva to Nice. That section eventually became the original GR 5 before later being extended northwards.
It would take many maps to cover the entire trail. For the Alpine section the French TopoGuides series 504, 530, 531 and 507 contain 1:50,000 scale maps of the whole route (and lists of accommodation, but in French).
Along the Alpine section water is generally readily available and the drinking fountains typically considered safe for foreigners as well as locals. If following the variant finish along the GR 52, for the last day into Menton, you must start with all the water you need for the whole day since there is only one spot that might have water and it is somewhat unreliable and used for watering sheep.
Fuel and cooking
Camping and refuges
There are numerous refuges and gîtes along the Alpine section of the route, offering comfortable accommodation.
Camping opportunities vary greatly since the route covers such large distances. Within the Alpine section; there are places where camping is forbidden and places where it is permitted but only after a certain time in the early evening (such as the Mercantour Mercantour National Park]).
As with all trekking: pack light!