Documentation at CodeProject:
The Dataset visualizer:
http://www.codeproject.com/Tips/578777/Visual-Studio-Visualizer-Part-1.

The Entity Framework SQL visualizer:
http://www.codeproject.com/Articles/584739/Visual-Studio-Visualizer-Part-2-Entity-Framework.

The List<> visualizer:
http://www.codeproject.com/Articles/599504/Visual-Studio-Visualizer-Part-3-Collection-visuali