This video playlist will walk you through how to use TestFit.
The TestFit UI
Finding your site
Defining your site from parcels
Site Polyline tool
Add a background image
Site Cutting
Adjusting Setbacks
Adjusting Dynamic Units
High Density Manual Mode
Creating Custom Units
Adding Backgrounds to Custom Units
Custom Garden Buildings
Massing Mode: How-to
Adjusting Industrial Buildings
Industrial Manual Mode
Adjusting Deal Information