I would recommend you start doing rather than studying. You can always start with hosting your own stuff which will force you to figure out how to deal with the unforeseen problems you are unlikely to find in any books.
I have been involved in hosting for 18 years, setting up thousands of servers and just about every hosting related concept there is, and I still run into situations that pop up that had never popped up before.
When I started doing hosting, I only had a useful level of knowledge of Linux. There were no control panels (that I knew of) and even RPMs were just starting to exist... You can always figure out stuff as you go and if you do it with your own content, then that will drive you to fix things quicker.
Once you feel like you can keep things online in a stable manner, then you can delve into hosting others.
My $0.02.
JoseQ