I'd recommend perusing a photo-filled contemporary analysis first and then reading a modern one which I've summarized to give the necessary background to understand the Czech defensive scheme.
More photos of some of the smaller defensive works are available, but be advised that some of the photos are quite large.
Some of the graphics need to be worked on to improve their legibility, but I've uploaded them anyway to give you an idea of what's under discussion.
A page on the Czech Fortifications that goes into much more detail than mine. Links to a number of Czech-language sites are available on my links page.
Jason Long
An analysis of the aerial correlation of forces in October '38 is also available.