"Writing and Querying MapReduce Views in CouchDB" is the book you need if you found that the sujet wasn't explained enough in "CouchDB: The Definitive Guide". This book covers with more details how views get built and requested in CouchDB.
All exemples from the book are provided both in CouchDB web interface (Futon) and on the command line with cURL. That allows to show both a user friendly interface and to dig in more details CouchDB usage of HTTP protocol to display documents.
The first part of this book presents how MapReduce is used to create views. Thoses views are an advanced type of indexes. The last part, and the most interesting one, concentrate on the way to take best advantage of views for accessing stored documents over HTTP.