The quickstarts demonstrate JBoss EAP, Java EE 7 and a few additional technologies. They provide small, specific, working examples that can be used as a reference for your own project.
To make it a quick start for you, I recorded a little 6 minute screencast about how to use JDBS to deploy the HelloWorld quickstart.
The quickstarts cover a lot more. So. make sure to check all of them and read the documentation before you start working with them.
Developers can download JBoss EAP 7 with a jboss.org account. They also need to accept the terms and conditions of the JBoss Developer Program which provides $0 subscriptions for development use only. Find out more about the JBoss Developer Program.
And while you're downloading, here are some more resources to get your started: