This Tutorial is most relevant to Ext JS, 2.x, 3.x.
For those of you who would like to use Eclipse as an IDE for developing Ext-JS applications, this tutorial details the initial setup. This tutorial assumes that the reader has knowledge of setting up projects in Eclipse environment. Also this tutorial assumes that the Ext-JS has been downloaded to your computer.
Eclipse Dynamic Web Project Directory Structure
+ << Web Project Name >> - build - src - WebContent - css - images - js - META-INF - WEB-INF - examples
1. Create a Dynamic Web Project in Eclipse.
2. Create the folders "css", "images", "js" and "examples" as shown above.
3. Copy "examples.css" and "ext-all.css" to css folder.
4. Copy the images directory from <<ext installation>>\resources folder.
5. Copy "ext-all.js" and "ext-base.js" into the js folder.
6. Create your own html page under examples directory based on the template html file shown here  .
7. Deploy your Web Application to Apache Tomcat or any other Web/Application Server of your choice
8. ENJOY THE POWER OF EXT-JS.