You can find formal reviews of this book at Ruby: Visual QuickStart Guide, by searching online. or through any other site that sells my books. Here are a couple of recent comments I personally received from other readers regarding this specific book:
Congratulations on Ruby Visual Quickstart. I just started getting my feet wet with ruby two weeks ago. I have prior C++ and Java background, though I am not a professional programmer. I have three other popular ruby books, but in my opinion RVQ is the best organized, straightforward, and most suitable for “adult” ruby newbies.