To be able master in OAF , you need to learn the following things
1) Core Java
2) J2EE ( Just Basic of servlets and JSP , and intro EJB )
3) Design Pattern ( intro to MVC Architecture )
Then Jump into OAF , Oracle provides the tutorial tool box to learn OAF concepts , it's shipped along with Jdeveloper Patch .
If you come across any doubts , you are free to post thread in forum . Happy Learning and Good Luck .
I am sure you have an EBS instance to start with ,
If you have I suggest you to start with the tutorial guide which will come with the Jdeveloper folder you download.
Check the Note Note 416708.1 - How to find the correct version of JDeveloper to use with eBusiness Suite 11i or Release 12.x
to download the right Jdev.
And you can search in this forum itself there will be many link for start learning OAF.
please go through similar threads on OTN Forum.
Learn OA Framework
To start with oaf definitely we require Core Java, Design Pattern knowledge then we should jump into tutorial tool box practise exercises.
I already have the knowledge of Core Java and MVC Architecture. Now i need to install Jdeveloper in my local system.
Good to know
Since you 're from java back ground you can kick start oaf , please make sure that its very essential to download the exact version of
Jdeveloper which is compatible to your Oracle EBS and have Jevelopers guide for reference .
Have a good go .