There is currently a book on Construct put out by HobbyPress, but I haven't read it, and I do have some doubts about how comprehensive it is.
I'd love to be a "user feedback" editor of sorts for you, and lend you a hand on some of the most important aspects of a tutorial that even the best tutorial writers completely miss on a regular basis:
1. Having clear step-by-step instructions--with screenshots for critical aspects--that don't assume the reader already knows or understands what to do. This one missing piece pretty much destroys every tutorial for the beginner, and unfortunately most tutorials on the internet are like this.
2. Staying away from speaking in an overly technical manner in a way you'd expect from a person who is highly experienced with the program and/or has many years of programming experience in general. Why? Because like #1 it assumes that the person reading is going to know what you're talking about, though the reality is that they won't 9 times out of 10 which makes the tutorial practically useless for them.
3. Explaining what a specific action means, what it does, and why you're using it, and only from the perspective of what it means to Construct, not the broader idea of programming in general since it will only confuse the reader with a lot of non-Construct specific information that won't help them build anything in Construct. Let me make an example:
Say I'm a total beginner and I ask you what a Global Variable is, and you then explain it in it's deepest technical terms. You've just wasted the reader's time, because what the reader wants/needs to know is A. What is a Global Variable in the context of Construct, B. Why does he need to use it in Construct, and in what situations does he need to use it? C. What are the clear steps to creating one, step-by step?
Without A, B, and C, the tutorial is incomplete, and of course for the beginner without a step-by-step it's entirely useless.
I find that those 3 missing components make even the most content-heavy tutorials unhelpful. Tutorials are too often written without regard to the way a beginner is thinking and how a beginner will likely interpret information they've never seen before, so it winds up just being incomplete or lacking thorough enough explanations.
As one last piece of advice, I'd say that the book should be accompanied by two things: 1. Any tutorial in which a specifc type of feature is created (i.e. Mode 7, Game timer clock, etc.) it should be accompanied by A. The information on the version of Construct in which the feature was created and B. A .cap file (with the information present telling the reader what version it was created in), because example .caps always enhance a text explanation.