Deepak Vohra has published three NoSQL books.
Please have a look if they could be of interest for you!
NoSQL Web Development with Apache Cassandra
Pro Couchbase Development
Pro Couchbase Development: A NoSQL Platform for the Enterprise discusses programming for Couchbase using Java and scripting languages, querying and searching, handling migration, and integrating Couchbase with Hadoop, HDFS, and JSON. It also discusses migration from other NoSQL databases like MongoDB. http://www.apress.com/
Pro MongoDB Development