There are two sites which support The Bible Challenge. The first one is cited in the book:
It has a place to enter an email subscription but every time I try it, I get an error message and I can’t find a place to correct it.
The second site does not, as far as I can tell have an official relationship to the book, but I certainly could be mistaken. Its cycle starts anew on Jan 1, 2015 and the Scripture readings are posted right there online. It does not include the meditations which makes sense because they want people to buy the book after all.
This site is: http://www.thebiblechallenge.org/