This book is excellent for those who have never played with Clojure and are curious about ClojureScript. The section on macros really gets to the marrow of the concept so you can start writing them quickly (although I wouldn’t recommend stoping there. Macros are an art onto themselves and really deserve further study). The authors of the book are solid members of the Clojure community so you can trust there expertise. From my vantage I felt the code examples are spot on , clean and well written.
If this book gets you going, I highly recommend Oreilly’s “Clojure Programming” and Pragmatic Bookself’s “Programming Clojure”. Both are excellent choices to deepen one’s Clojure skills.
If you are further along the learning curve of Clojure and want to start with ClojureScript , this will be a quick read. Maybe too quick. I would recommend checking out the ClojureScript One project. It is a fantastic way to start working with ClojureScript. I may be wrong but I believe the authors of ClojureScript: Up and Running are involved with ClojureScript One as well.