This is my first book into the world of OCaml, and I guess I was lucky enough to read the second edition published just recently, so things in this book are fairly relevant and comprehensive, compared to other books on OCaml.
With experience in other languages, like C/C++ and Python, and some basic knowledge in PLT (programming language theory) and FP (functional programming), I found this book organized in a logical way and relatively easy to read. But sometimes I still struggled to follow and had to read over and google, since OCaml is quite a different language from popular ones.
Overall, I think this book is worth reading and could get you started with OCaml. I read the free online version, in which I did notice a few minor typos and code examples that didn't run on OCaml 5.0. Yet such defects should not obscure the good. It's a great book.