This is a book I published about six months ago now that provides a high level guide on how to plan and move to Cloud services. Starting from the beginning it looks at what Cloud is, how to target services for Cloud, the risks & roadblocks, getting ready, sample project plan, sample architecture, where the Cloud is going, how to change your ICT organisation to manage it, and a sample risk model.
Now for the caveat. The book was published about six months ago so its starting to get a little bit dated, keep that in mind when you read it. A new version will be published later this year.