Felix’s Node.js Guide http://nodeguide.com/
Node.js Beginner Guide If you are new to node.js, this guide will take you from hello world to deploying your first app.
Node.js Community Guide Get to know some of the node.js community and find out where they hang out.
Node.js Convincing The Boss Guide Find out where node.js makes sense, and how to get management to see the benefits.
NodeJS – The what, why, how and when http://blog.xebia.com/2011/08/16/nodejs-the-what-why-how-and-when/