No really: How do you USE it? I get the basics: EC2 VPS for computing power, and you get to pick a stack from a list of AMIs or customize one to fit your needs

No really: How do you USE it? I get the basics: EC2 VPS for computing power, and you get to pick a stack from a list of AMIs or customize one to fit your needs, S3 for storage, ClouFront CDN for better global distribution, but whenever I want to take a closer look, I feel so overwhelmed by the options that seem to be increasing over time. What's the best reading material to get a solid, up to date foundation?