Along with the release of Monad B3, I've been reading through Monad a new book by Andy Oakley, published by O'Reilly. You can read the Press release about this book here. Although Andy must have forgotten when he wrote the intro, I was one of the reviewers of this book - and I'm pleased to see the book published.
The book is a really good introduction into the basics of Monad. It's short (around 150 pages), provides a great introduction to the langage and to the MSH shell and is accurate wrt Beta 3 (it was written around B2, but so far I've not found anything in the book that does not work in B3). I found reading at the keyboard and trying out the code samples was a great way to learn more about Monad
The book does not do any deep dives, such as details on extending the shell, or how to host Monad in your own application. Andy had written a chapter on extending Monad, but it was not published (and would have been overtaken by events anyway). But as a great introduction to Monad and starting place for admins who want to learn about Monad, this is a good book to have!