Two Books worth Buying, I have both, both are excellent.
EOS 5DMK III James Johnson (Rocky Nook Books)
5DMK III Digital Field Guide Charlotte Lowrie (Digital Field Guide Series)
Both available from Amazon as Books or as a download.
Couple of excellent Videos Volume 1 & 2 available as downloads or streaming Video, Volume 1 is available as an Ap for iPhone, unfortunately Volume 2 is only available as a streaming Video, find them at "Blue Crane Digital".