It is a short book, that explains 10 simple MapReduce application patterns. The book starts from the ground zero, introducing MapReduce. Then it goes on to MapReduce patterns.
The book aims to get reader beyond the word count (the hello world equivalent in the Map Reduce world) and give them a concrete feel into writing MapReduce programs. There are three introductory level recipes, and then it describes seven patterns of MapReduce programs: analytics, set operations, cross correlation, search, graph, Joins, and clustering with an example on each pattern.
Hope it will be useful, I will blog later about sample recipes.
Also if you are looking for a detailed treatment, our earlier book "Hadoop Mapreduce Cookbook" might worth a look.