So I’ve been doing a bunch of presenting around the Cloud Recently and also starting to discuss it as a platform with a number of our customers.

I thought I’d put together a blog post on some of the key reading I’m getting people to do to come up to speed.

http://berkeleyclouds.blogspot.com/2009/02/above-clouds-released.html
Is an academic white paper out of Berkeley. Well worth a read and I’d probably start your journey here.

It’s also important, no matter which platform you choose, that you have a good understanding of how to build horizontally scalable systems and that you understand why and how to partition your stateful data tier.
I quite like the recent O’Reilly book Beautiful Architecture  for an overview of this with worked examples

Other stuff that’s worth reading include:

The Primer on Scale from Wikipedia is useful
http://en.wikipedia.org/wiki/Scale_out#Scale_vertically_vs._horizontally

Choosing Partition Keys
Some Thoughts on Choosing Partition Keys in Windows Azure's Table Storage

And Also from Dare: On ‘Trusting’ The Cloud
Asking should we trust the cloud is like asking should we trust horseless carriages

If STS’s, IP’s RP’s and other identity acronyms are Dutch to you then Vittorio’s article on Claims is well worth a read
Claims and Identity, On-Premise and Cloud Solutions