Best way to approach installing a distro across multiple machines?

In my house, I just go to each machine individually, install the distro, and set it up. I have 5 machines, so this isn't too painful, but this obviously wouldn't be ideal for hundreds of machines :p

I've never learned about network boot, and for the longest time, it was just an option I usually left disabled under the BIOS.

I plan on reinstalling Ubuntu across all my machines once 16.04 comes out, and would love to try out some kind of mass-install method, but don't really know where to start.