Suneel, you'd have an easier time cleaning out the Augean Stables than learning 'all' of JDE World. You can buy the JDE World Administrator's Guide on Amazon if you only want to learn the technical aspects of security, menus and wrapping dreamwriters around programs. But that will not teach you how to program within JDE. And that still leaves the entire body of functional knowledge. There is no single, organized body of JDE World functional knowledge. The only way to really learn JDE is to be taught by someone who knows JDE. If you are really being thrown into JDE support by your employer (per Mr. Landess's comment) with no training, I'd like to know who that employer is so I can avoid them.