There are few English guides that go into detail about the Tokai trail. The majority of the guides are in Japanese,

I have found a few guides that I think are useful in learning a bit more about the trail.

 

There are a significant more trail guides in Japanese, ranging  from casual blogs to detailed step by step guides to the trail. I have included the guides that I used the most on preparing for the hike. Even if you do not speak Japanese I would consider going through some of them, as they do offer great photos, and maps of the trail.