This book could be a good reference for someone who is more advanced in the Punjabi language. Simply look up the Punjabi word and learn what it means in English quite easily and quickly. I did not find the colloquial expressions the back cover says it has. The book is divided into two parts, one half is the Punjabi to English dictionary and the second half is English to Punjabi but written in Gurmukhi.
If you know the English word and wanted to learn the Punjabi equivalent, well, this book is definitely not helpful unless you can read Gurmukhi. For me, a beginner, I found the book did not serve my purpose, and was not what I expected. I did buy this online, and the seller highly recommended this as the best book for any first timer who wanted to learn the basics. It is a thick, heavy book and not easy to carry around. I will probably give it away and search for a dictionary or reference book that is written entirely in English.
I think the book, which really is a dictionary, is an aid for the Punjabi speaker. I did find 'Learn Punjabi in 30 Days' taught me a good number of phrases and useful expressions set up in a simple method. That was a great start for me.