Good question, and yes, the website probably should contain info about the target audience. I'll look into it tonight.
Is this book for JavaScript newbies? If you're already a programmer, yes. The book contains a whole section on "JavaScript for programmers", which deals with a selection of JavaScript topics. This part shows the parts of JavaScript that makes it different from other programming languages, and uses
unit tests to illustrate behavior.
This book is probably a little bit too dense if you've never programmed at all, but I suspect that won't be a problem for you guys