[codr]

If what you're really after is designing a scalable website - which is very different from system admin stuff - I think the "Building Scalable Websites" book is a great place to start: http://shop.oreilly.com/product/9780596102357.do

Perhaps a bit dated (2006), but most of it would still be relevant.

[ycombasks]

Would I need to know how to do a lot of administration tasks? For example, when getting an ec2 instance, I pretty much have to build the whole server myself. That means I need to know how to secure it properly from hacking, as well as set up clusters, all the software (apache, nginx, haproxy, etc) with the right configuration, etc.

Additionally, when something breaks in the middle of the night, I'm going to need to know how to troubleshoot it. What do you think?