Resources for learning load balancing and building scaleable web apps?

Hello. I'm a skill and competent programmer but haven't really delved into the realms of server administration beyond a single server. I'm working a project that requires me to scale an app across multiple servers as traffic increases and want to know some resources for learning the ins and outs. Books, online resources, etc. Load balancing, database clustering federating or whatever the terms are, software architecture and how to go about administrating the servers, etc.

I want it to be similar in nature to google's app engine in that once the app is built it scales automatically and I don't need to modify the code after the fact as things get bigger.