I just picked up Node.js about 2 weeks ago. For reference here is the "stack" I am using:
-Node.js
-Expressjs
-Jade Template Engine
-Mongoose as my wrapper for MongoDB (a "NoSQL" database)
I have been loving it so far and I came in with only a basic working knowledge of Javascript with a little jQuery experience.
I have to say right off the bat, don't use CoffeeScript. I tried it and a friend of mine who started Node.js at the same time tried it. While it is very interesting, it is still buggy and the code it produces isn't a great style (in my opinion). The biggest reason not to use it, is that Javascript is a "C" syntax styled language and if you can learn the general syntax of these kinds of languages, you will be doing yourself a HUGE favor and you will find your abilities better able to translate to C, C++, Objective-C, C#, PHP and others.
Good luck with learning! It's a great choice from my opinion.