While long, these articles include lots of interesting reports, recommendations and survey material:
Cloud computing is an on-demand service model for IT provision, often based on virtualization and distributed computing technologies. Cloud computing architectures have:
- highly abstracted resources
- near instant scalability and flexibility
- near instantaneous provisioning
- shared resources (hardware, database, memory, etc)
- ‘service on demand’, usually with a ‘pay as you go’ billing system
- programmatic management (eg, through WS API).