This repo contains the MapReduce example. This will need an HDInsight cluster to run on and a storage account loaded with the dataset.
The repo contains a project for a console applications, Runner.exe, a class library containing the map and reduce implementations and a Test suite for the library.
In order to connect to your cluster you will need to change the connection details in the Runner app.config.
To use the PowerShell scripts you will have to setup your Azure PowerShell cmdlets, and also provide passwords and keys in a file called secrets.ps1 in the same folder as the samples here. I've included an empty template for the secrets.ps1 file as secrets_template.ps1, just fill in the variables where I've left blank strings.