Architecting The Cloud. Design decisions for cloud computing service models, by Michael J. Kavis describes cloud computing in general and the different service models that are prevalent today in particular. It explores the differences and trade-offs between Software as a service (SaaS), Platform as a service (PaaS) and Infrastructure as a service (IaaS). I consider the book a good introduction to considerations for cloud computing for those that are used to more traditional data-center deployments.
The author covers a section on worst practices: Things that do not translate well when moving to the cloud and recommendations on how to avoid them. I found the most useful chapter to be the one on disaster recovery: A good overview of different strategies to become fault-tolerant in the cloud and embracing resiliency.