This compact and focused book offers a good introduction into the NoSQL landscape. It covers the motivation for NoSQL data store, discusses characteristics and differences to classical relational databases and then dives into a rather hands-on comparison.
I most enjoyed the chapter 5 'Comparative Study of NoSQL Products' as it provides a detailed side-by-side comparison over a range of data stores, from Amazon's SimpleDB over HBase to Neo4j. This comparison covers not only the (obvious and expected) hard facts and technical features but also YCSB performance and scale results, security features, encryption, multi-tenancy support, and in addition, very useful soft facts around community, support, and licenses. The book closes out with an interesting end-to-end case study, valuable for beginners and practitioners alike.
I can wholeheartedly recommend this book if you're new to the field, but also if you have already gathered some experience with one NoSQL datastore, say, MongoDB, and now wonder what alternatives there are and/or what to use when. See [...]