I'm mostly finished with a canvas tent I made -- first "real" sewing project -- and thanks to this site and others, I was able to figure out pretty much everything I needed to know. Sailmakers' sites and sailmaking books were also great references. Same for parachute-makers.
Unfortunately, after spending an hour or so looking through "sewing books" at the store [after the fact], I found almost nothing useful for anybody making gear. If it even comes up, the word "reinforcement" is used in these books as a catch-all, without any real meaning.
Meanwhile, I needed to know things like when and why to use a flat-felled seam; when to use a bar-tack versus a box-x versus the W patterns, and how they hold up. Or even more basic stuff like which thread to use; when to use a straight, zigzag, or 3-step zigzag stitch; and how to set the tension properly. And tips and tricks like "how do you actually sew through 11-20 layers of 10oz canvas without breaking a needle by deflecting it into the throat plate?" E.g., joining 2 flat felled seams and a reinforced hem... (I actually had to buy a new throat plate, since I broke it.)
Granted, I figured most of that out -- even if using completely inefficient techniques. There's a few Frankensteinian corners on that tent.
So now that I'm effectively done with this project, are there any books that actually explain how to do any of this stuff?