When my darling lab mix died recently, I bought several books on pet loss grief recovery and this one helped me the most.
What helped me about this book were two things, which I'll mention first, and then explain. Those two things are:
1. The workbook questions.
2. The unique, balanced tone of this book.
Now I'll explain:
The workbook questions - This is a highly interactive book. You don't just read it passively. At first I thought the questions would hurt too much to do (one of the questions has you write the story of how you came to choose your pet above all others), but as I wrote out my answers to them, I felt better. I also felt happy as so many wonderful memories of my dog flooded back to me through the tears.
The unique, balanced tone - The other books I read seemed either too uncaring or -- at the opposite extreme -- too sad. Instead "How to ROAR" is written by a highly empathetic author who also helps you to work through the grief and get to "acceptance" stage (and beyond) at the other side.
In conclusion, if you've lost your pet (or know someone who has), get Robin Jean Brown's book. It will help to work through the pain and heartache.