Node.js is an open source, cross-platform runtime environment for server-side and networking applications. Node.js applications are written in JavaScript, and can be run within the Node.js, ok I've got that out of the way, Node JS is great BUT it can be a little bit overwhelming at the beginning. I've pulled together this guide just to try and get some getting started stuff in the same place.

Node itself : https://nodejs.org/

A great way to get started is with the nodebeginner book.

http://www.nodebeginner.org/

Felix Geisendörfer has a great site,

http://nodeguide.com/beginner.html

Tuts Plus : http://code.tutsplus.com/tutorials/nodejs-for-beginners--net-26314

CodeSchool: https://www.codeschool.com/courses/real-time-web-with-node-js

Books

Pedro Teixeira

Professional Node.js: Building Javascript Based Scalable Software -
http://www.amazon.com/gp/product/1118185463/

Azat Mardan

Express.js Guide: The Comprehensive Book on Express.js - http://expressjsguide.com

JavaScript and Node FUNdamentals - https://leanpub.com/jsfun

Practical Node.js: Building Real-World Scalable Web Apps- http://practicalnodebook.com

Tutorials

There are some great tutorials out there for Node, I've pulled a few together here.

http://cwbuecheler.com/web/tutorials/2013/node-express-mongo/

Part 1 – Introduction to Node.js
Part 2 – Welcome to Express with Node.js and Azure
Part 3 – Building a Backend with Node, Mongo and Socket.IO
Part 4 – Building a Chatroom UI with Bootstrap
Part 5 – Connecting the Chatroom with WebSockets
Part 6 – The Finale and Debugging Remote Node Apps