The Teach Yourself Logic 2016 Study Guide was viewed an astonishing 51K times and download 3K times from my academia.edu page last year. It was also downloaded another 1.4K times from this Logic Matters site. I guess (or at least, hope!) that some people, somewhere, have found it useful.
Taking a quick look at last year’s version, I haven’t found myself moved to make significant changes right now (partly that’s because my mind, or at any rate the logical bit of it, is so taken up with thinking about IFL2). So the Teach Yourself Logic 2017: A Study Guide (find it on academia.edu by preference, or here) is only a very modest “maintenance upgrade”.
But I must eventually give some thought as to whether it is best to continue with the Guide as a single long document. On the one hand, despite the friendly signposting, 90 pages could seem very daunting. On the other hand, different readers will come with such different backgrounds, interests, and levels of mathematical agility that it is might still seem best just to plot out long routes through the material, all in one place, and (as I do) invite people to get on and off the bus at whatever stops suit them.
Oh, and another thing. I know that you don’t want to extend the guide too much, but perhaps Kripke-Platek should be mentioned in the section on alternative set-theories? I know it’s not an alternative in the foundational sense, but it’s nevertheless a rather important set-theory-that’s-not-ZFC, so maybe a quick mention is in order. Plus, I personally found (some bits of) Barwise’s Admissible Sets and Structures rather approachable once you know a little of set theory and computability, so there’s a rather standard book to make reference to.
Here’s a 2016 book that probably should be mentioned in the Computability section (and, incidentally, also belongs to the “logic book of the year” list): Robert Soare’s Turing Computability: Theory and Applications.
Many thanks for the pointer: not sure how I missed this!