After reading all the posts, all I can say is "Great Job!" I have been struggling with C for 5 years off and on, have bought and read through a number of c books, but ALL OF THEM assume things that you aren't assuming.
I have been fairly successful in RB, and even in Cocoa, but have felt the pains of C and the books make so many assumptions, I have missed the point trying to figure out the basics. These are the things you spend 5 seconds on when there's a programmer or teacher next to you that you can ask questions like (why is the header there in the first place? and why is it in a separate file sometimes and not in others), but can keep you from figuring out an example code snippet if that answer has never been provided.
By getting to these assumptions, the reader will be equipped to then read and perhaps understand and see how they can use C&R if they want to. This gets them building something that can excite them enough to make them scratch their heads with C&R. All I would hope for is a daily instead of monthly article, not less detail. The level of assumption is perfect, just bring it more often. Like many have said