@Gary Pilsworth: This is the final diagram in the construction sequence for my Razorbank model (which I'm finally able to continue working on). Click my signature for pictures of an assembled model.
I did a longer search and came up with a couple of references.
This one shows a variety of different types of instruction diagrams:
The Art of Paper Model Instructions
These pages illustrate the work of one particular artist in a purely visual approach (his line style is also the same as the second picture I've shown, though his shading seems different):
Paper MP-5 | PostlerFerguson
Paper Uzi | PostlerFerguson
Paper M4 | PostlerFerguson
Paper Mills Bomb | PostlerFerguson
Paper AK-47 | PostlerFerguson
I've also located tutorials on the process of designing paper models. However, these gents don't particularly go into the informatics of it.
Julius Perdana - His assembly diagrams are 3d colored renderings of the parts
Tutorials
Robert Nava - Instructions are black/white renderings of 3d parts aided by portions of text
Nava Designs
If anyone else has some nice references or how you make your own diagrams feel free to contribute. Ruben actually built my first model the Anvil and he included a pic of all the pages where you can see what my first diagrams were like. Of course you can just download it yourself for a better idea.
Anvil, from Papersmith Forge