I recently bought this book and have been using it to make a mixed stitch stripey blanket. I definitely recommend it; I bought it for exactly the reasons that you're describing, i.e. to learn a bunch of new stitches.
The Amazon page says it's paperback, but it's not a true paperback. It's got a thicker cover so you could definitely get away with keeping it in a bag. That being said, it's definitely not hardcover. It's kind of just a floppy, more durable paperback?
There aren't any mistakes that I've found in the book so far, and I've probably tried like 30 or so stitches from it? Maybe more? There have been a couple where I've tried to read the book but ended up just YouTubing it, and I think the combination of the book + videos on YouTube has been helpful. I do really like though that the book has a picture of each stitch, the stitch diagram for it, and then the written pattern for it. It's been good for learning how to read diagrams since it has all three things on each page.
At the beginning I used three sources for inspiration: little woolie's mixed stitch blanket, Not Your Average Crochet's stripey blanket, and a book called Basic Crochet Stitches. Now I'm really just using the book mostly; the blankets from the two blogs are really repetitive, as are many of the stripey blankets you see on the sub. That wasn't really what I was going for, so I bought that book off of Amazon (which is actually the book that one of those bloggers used for inspiration; they just don't use very many stitches) and I've been kind of going with whatever suits my whim at the moment!
I got the Harmony guide to crochet stitches (https://www.amazon.com/Harmony-Guides-Basic-Crochet-Stitches/dp/1596680814) and put rows of some of those into scarves and such when learning new stitches.