Welcome to the forum
@Joanne P - saw your other post but this is a better place to reply. For planning purposes you are probably best to start reading through the various threads on this forum in the Le Puy section. Then, as you become more familiar with the forum you could venture into the Camino Francés section - which is huge - and covers the route from St Jean Pied-de-Port to Santiago de Compostela. The search function is also very useful once you master it, and tags can also be helpful.
Most people who walk from Le Puy rely on the Miam Miam Dodo book for information about accommodation and services - it is in French but very easy to understand. It is updated annually and lists all accommodation within 5km of the path, together with services (supermarkets, banks, shops, taxis etc). It also has schematic maps with distances which were enough for me, but some people found too simplistic. Available through Amazon France
here. There is also an app but I can't download it in my geographic region very easily.
More detailed map guides come in various other guide books - the
Topo guide, the
Michelin guide are two.
As you are not going until 2018 I would wait before buying any guidebook because they are constantly updated, and you want the latest one. Although the route remains the same accommodation changes all the time, and it is also useful to have up to date information on services.
This is just the start of a beautiful journey! Buen Camino.