The Little MongoDB Book in pdf

Most of this book will focus on core MongoDB functionality. We’ll therefore rely on the MongoDB shell. While the shell is useful to learn as well as being a useful administrative tool, your code will use a MongoDB driver.

This does bring up the first thing you should know about MongoDB: its drivers. MongoDB has a number of official drivers for various languages. These drivers can be thought of as the various database drivers you are probably already familiar with. On top of these drivers, the development community has built more language/framework-specific libraries. For example, NoRM is a C# library which implements LINQ, and MongoMapper is a Ruby library which is ActiveRecordfriendly. Whether you choose to program directly against the core MongoDB drivers or some higher-level library is up to you. I point this out only because many people new to MongoDB are confused as to why there are both official drivers and community libraries - the former generally focuses on core communication/connectivity with MongoDB and the latter with more language and framework-specific implementations.