First, learn the core concepts of Node.js:

• You‘ll want to understand the asynchronous coding style that Node encourages.

• Async != concurrent. Understand Node‘s event loop!

• Node uses CommonJS-style require() for code loading; it‘s probably a bit different from what you‘re used to.

• Familiarize yourself with Node‘s standard library.

Then, you‘re going to want to see what the community has to offer:

The gold standard for Node package management is NPM.

• It is a command line tool for managing your project‘s dependencies.

• Make sure you understand how Node and NPM interact with your project via the node_modules folder and package.json.

• NPM is also a registry of pretty much every Node package out there

Finally, you‘re going to want to know what some of the more popular packages are for various tasks:

Useful Tools for Every Project:

• Underscore contains just about every core utility method you want.
• CoffeeScript makes JavaScript considerably more bearable, while also keeping you out of trouble!
  • Caveat: A large portion of the community frowns upon it. If you are writing a library, you should consider regular JavaScript, to benefit from wider collaboration.

Unit Testing:

• Mocha is a popular test framework.
• Vows is a fantastic take on asynchronous testing, albeit somewhat stale.
• Expresso is a more traditional unit testing framework.
• node-unit is another relatively traditional unit testing framework.

Web Frameworks:

• Express is by far the most popular framework.
• Meteor bundles together jQuery, Handlebars, Node.js, websockets, mongoDB, and DDP and promotes convention over configuration without being a Rails clone.
• Tower is an abstraction of top of Express that aims to be a Rails clone.
• Geddy is another take on web frameworks.
• RailwayJS is a Ruby-on-Rails inspired MVC web framework.
• SailsJS is a realtime MVC web framework.
• Sleek.js is a simple web framework, bulit upon express.js.

Web Framework Tools:

• Jade is the HAML/Slim of the Node world
• EJS is a more traditional templating language.
• Don‘t forget about Underscore‘s template method!

Networking:

• Connect is the Rack or WSGI of the Node world.
• Request is a very popular HTTP request library.
• socket.io is handy for building WebSocket servers.

Command Line Interaction:

• Optimist makes argument parsing a joy.
• Commander is another popular argument parser.
• Colors makes your CLI output pretty.