There's a multitude of information available on the internet. This is just a small sample.
The Canadian Company of Pilgrims have an excellent website with downloadable guides dealing with subjects like camping, luxury hotels, etc. They even have a recipes page!
There's also an excellent blog with tonnes of additional information here
And, of course, the Pilgrims Office in Santiago have an official statistics page, which is also very interesting.
This is the website of the Amigos del Camino.
The Jacobeo website has lots of information if you can find it.
Les Amis du Chemin de St Jacques in St Jean Pied de Port also produce a list of pilgrim accommodation which they update every year. It can be downloaded from the Xacobeo.fr website.
Here's a video of the Botafumeiro in Santiago cathedral.