OM and AR reports

[nagul]

Hey all,
I am new to Ora Apps and about to get in to market.
I am preparing for interviews and would request every one of you to help me if possible.

First I would like to what kid of questions I can expect on reports ?
and also
I like to request to specify some of tha reports in OM and AR that can be customized and what all real time issues will occur when some one try to register the report.

Please...

Thanks.