Subscription Level Template deployments is relatively new feature. Support for Azure CLI was added in version 2.0.40 and for AzureRM PowerShell module is yet to come. Basically instead of deploying resources at resource group you are doing that at subscription level. This opens a lot of possibilities some of which are:
Here is a great article where are gathered links to a training materials for PowerShell. The resources are provided in a form of contents. If you want to learn PowerShell and spend minimum finances start by opening this article
In order to start building Cloud you have to have resources. Such resources are storage, network and compute power (servers). Let’s say you have those but the servers are nothing without operating system. The operating system connects these resources together. To get the OS on a server you have to install and configure it. But if you start to install and configure OS on every server manually it will be resource intensive and could lead to inconsistency in the configuration of your servers. Of course there is solution for this problem and it is called automatic deployment. Microsoft offers such solution and it is free – Microsoft Deployment Toolkit. MDT offers full automation in deploying Windows but it can be integrated with System Center Configuration Manager to increase its powers in automatic OS deployment.
In the video below offered by Microsoft you will see Session 1 from Deployment day on Tech Days 2012 conference in Belgium. Presenter is Rhonda Layfield which is Sr. Deployment Architect. Video is Level 200 according to me and will show you the basics around MDT and what is new in 2012 version. Click on the link below and watch.