This article will help if you want to know the more in-depth features of Pro-Tools such as understanding Channels, Plug-ins, Elastic Audio and Rewire. These videos refer to Pro-Tools First but are also relevant to Pro-Tools. 

Where can I find Pro Tools | First?

Getting Started

Channels

Plug Ins

Elastic Audio

Rewire

For further help with Pro Tools First, please see Avid's help pages here.