I recently read the Cloud Computing Bible by Barrie Sosinsky. It is a comprehensive resource on all aspects of cloud computing, both public and private, and is about 20% business information and about 80% technical information. I found it to be both readable and an excellent reference book.
There are substantive explanations of a variety of cloud computing concepts including references for getting further information. I found the sections on Cloud Security, Service Oriented Architecture (SOA), and Moving Applications to the Cloud particularly useful.
There has been a lot of discussion about a service oriented architecture being a prerequisite to enterprises moving applications to the cloud. This book explains quite clearly what the connection is and why it is important, especially for non-SaaS cloud applications.
There are also explanations of various types of cloud application areas including cloud based storage, productivity software, collaboration services, streaming, and mobile. Examples and explanations are given for the major categories.
I found the in depth descriptions of Google, Microsoft, and Amazon services very helpful and interesting. The substantial real world examples throughout the book were excellent as a companion to the more academic concepts.
This book was published in 2011 so it is very up to date but in a field as rapidly changing as cloud computing some of it will rapidly become obsolete. Right now it is a great resource that I would highly recommend that you read in detail or that you add it to your reference bookshelf.
It is published by Wiley Publishing, Inc. and is $27.99 in paperback from Amazon and it is also available in a Kindle version.