I've applied for an internship at a startup company that expects its user base to grow by a large factor in a small amount of time, and so part of their project is to scale everything up so that they're ready: handling more/larger requests efficiently, handling server failures, load balancing, getting more JavaScript to run faster on the client computers, etc.

Part of my job will also be figuring out what to do, so it's not obvious what my exact task will be at the moment. I was told that I should start reading up a little more about this so that I would have a little bit of an idea of what to do. What are some good books for me to read on this topic?

I have a little bit of experience with the usage of MySQL (and also a little experience with web development), but in no way do I claim any knowledge on the internal workings of databases or distributed systems, so I might need readings more on the introductory side.