Instructions for setting up a basic Apache environment on OS X Yosemite Only. For Mavericks, view this guide
For this guide, square brackets are used to denote places where you need to plugin your own stuff. In none of these cases are you supposed to use actual square brackets.
Note that /private/etc and /etc go to the same place on Yosemite. This is good to know for later.
If you've already configured Apache correctly and you just want to know the part about setting up a new Virtual Host, then you can skip to that section. If not, then you'll need to configure Apache.