Now that I got my head wrapped around the 'C' language to a point where I feel proficient enough to write clean code, I'd like to focus my attention on project architecture guidelines. I'm looking for a good resource that coves the following topics:

1. How to create an interface that promotes code maintainability and is extensible for future upgrades.
2. Library creation guidelines. Example, when should I consider using static vs dynamic libraries. How to properly design an ABI to cope with either one.
3. Header files: what to partition out and when. Examples on when to use 1:1 vs 1:many .h to .c
4. Anything you feel I missed but is important when attempting to architect a new C project.

Ideally, I'd like to see some example projects ranging from small to large and see how the architecture changes depending on project size, function or customer.

What resource(s) would you recommend for such topics?