My wife and I walked the Camino in May/June 2015. It was a fantastic, although sometimes a painful, experience. I highly recommend it. Weather was good. Some rain. Not so bad but unavoidable. Warm days and cool nights.
We used this book as a guide. It was the most popular English language guide used by the friends we made on the trip. Take it with you and read before for planning. It's fantastic.
https://www.amazon.com/gp/aw/d/1912216108/ref=dbs_a_w_dp_1912216108Some random advice:
Pack light. Very light. There are places where you can store items at the beginning or ship them to Santiago awaiting your arrival. Every pound matters. Some people even ripped pages out of their guidebooks for reduced weight.
Make friends along the way. It's incredibly helpful and one of the joys of the experience. That's not usually our thing, but it's easy when everyone is taking on the same challenge and journey together. Best to make friends at the albergues (pilgrim hostels) along the way, especially early on. Dinner is often served communally. And you sleep, often quite literally, right next to each other.
Wear knee braces from the beginning. I also recommend a hiking stick or poles. Your knees will thank you. Uphills are hard at first, especially over the mountains if you start on the French border in St Jean. After a week or so, uphills are a relief. Downhill is worse. Hiking sticks and poles help.
Leave early, early in the morning. Hostels and hotels fill up if you're late and you may not be able to find a place to sleep or use washing facilities.
Some places are cold at night, even in the summer but get hot during the day while hiking. Prepare to layer. A challenge when packing light.
Get a pilgrims passport and ask for stamps everywhere. It's fun. And it helps you remember. Lots of stops at churches and historical sites. Very moving and cool even for the non-religious.
Hike with your gear beforehand!
Buen Camino!
