Help for a SStarter!!!

Hi Hellow netters,
I am a beginner in Oracle. I know Cprogramming on both Unix and DOS env. I want to learn application Programming in ORACLE. I through my reading and knowledge understood that I can write the code in Pro*C. I am right now following the Pro*C User's guide version 1.1 for Oracle by Oracle Corp. That book has two parts one for C precompiler interface and OCI. Do I need to know the OCI if I am programming in Pro*C. Could you please clarify how I can incorporate SQL forms for User interface with Pro*C. Can I use any other Graphical User Interface like X. I prefer to work on Unix environment. Please pardon my total(??) ignorance in this matter. It would be great if you can clarify. Please let me also know if I am clear enough in voicing my queries.

Thanks very much in advance..

-- 
********************************************************************
	___  ___  ___
       /__  /__/  /
      ___/ /  / _/_  ***