Adding explanation for environments to README

Author: spacemonkey

README.md

@@ -1,12 +1,10 @@
 # MEAN Stack
 
-MEAN is a boilerplate that provides a nice starting point for MongoDB, Node.js, Express, and AngularJS based applications.  
-It is designed to give you quick and organized way to start developing of MEAN based web apps with useful modules like mongoose and passport pre-bundled and configured.  
-We mainly try to take care of the connection points between existing popular frameworks and solve common integration problems.  
+MEAN is a boilerplate that provides a nice starting point for [MongoDB](http://www.mongodb.org/), [Node.js](http://www.nodejs.org/), Express, and AngularJS based applications. It is designed to give you quick and organized way to start developing of MEAN based web apps with useful modules like mongoose and passport pre-bundled and configured. We mainly try to take care of the connection points between existing popular frameworks and solve common integration problems.  
 
 ## Prerequisites
-* Node.js - Download and Install [Node.js](http://www.nodejs.org/).
-* MongoDB - Download and Install [MongoDB](http://www.mongodb.org/) - Make sure it's running on the default port(27017).
+* Node.js - Download and Install [Node.js](http://www.nodejs.org/download/). You can also follow [this gist](https://gist.github.com/isaacs/579814) for a quick and easy way to install Node.js and npm
+* MongoDB - Download and Install [MongoDB](http://www.mongodb.org/downloads) - Make sure it's running on the default port (27017).
 
 ### Optional (Requirements for Grunt)
 * Ruby - Download and Install [Ruby](http://www.ruby-lang.org/)
@@ -55,6 +53,16 @@ There are three environments provided by default, __development__, __test__, and
 	* clientSecret
 	* callbackURL
 
+	To run with a different environment, just specify NODE_ENV as you call grunt:
+
+	$ NODE_ENV=test grunt
+	
+	If you are using node instead of grunt, it is very similar:
+	
+	$ NODE_ENV=test node server
+	
+	NOTE: Running Node.js applications in the __production__ environment enables caching, which is disabled by default in all other environments.
+
 ## Getting Started
   We pre-included an article example, check it out:
   * [The Model](app/models/article.js) - Where we define our object schema.