How does one create Help Documentation for an App created in Xcode and AppleScript?
This documentation should be available when user clicks the ‘Help’ Menu item. Can I create a PDF file, put it in Resources folder of the App and link to it? Howdo I do this using Xcode
Have a look through the archives here; it was discussed not too long ago.
No, but you could have the menu item call a script that opens a PDF. (The normal Help docs are HTML.)
It’s not too hard to do with iWeb and Help Indexer. 
I just looked into this a few days ago. I followed the instructions here and was able to implement it: http://www.ehow.com/how_7515811_do-add-xcode-project.html