Microsoft Virtual Academy and Microsoft Press have joined forces and have issued a number of free e-books on Azure – you can download them from the web (as PDF) and enjoy them on your PC/tablet/Phone/etc. You can get the full set of books from here: http://www.microsoftvirtualacademy.com/ebooks#azure.
Not sure how long
books will remain free – and how many of them are still up to date. Given the fast pace of Azure development, these books are almost out of date before you get them. But having said that, they are still worth reading.
At present I am looking at the book: Rethinking Enterprise Storage: A Hybrid Cloud Model. Although the book is now 18 months old, there is some good thinking here. It's certainly helped me to re-evaluate how storage works in a hybrid model and why that model is so useful for my customers.
So get reading!