Angel David Guzmán [PixelOz] has published a 227 page(!!) free e-book on the creation of paper models using 3D software. It focuses on Blender and even includes some sample files and a Python unfolding script.
This is a free e-book that I just finished writing about how to design paper models (card models). [...] It is 227 pages long and has hundreds of full color illustrations to help you understand the concepts of the e-book better.
The e-book also talks about the many different types of software that can be used to accomplish the task.
The most important thing that I discovered while researching the subject was that where new designers had the most confusion was not in some complex thing of the design process but in some fundamental principles that were not well understood and I set out to explain them carefully to give designers a head start, so here it is, free help for those that are trying to learn this art of paper model design.
I hope that this e-book really helps to make you understand the subject better.