akimtiaz,

A couple years back I did the same thing you are doing now. The thing you have to remember about Oracle Apps is that there are ALOT of differences between Apps and a regular database. Oracle Apps is a monster! Two things that stand out in my mind that kind of freaked me out when I first started.

1. Rapid install. Oracle in it's infinite wizdom basically designed a database and copied it onto a CD and that's what you're doing when you install Apps (just copying an already setup database onto your server).

2. The system tablespace. The first time I saw that I immediatly thought that someone didn't assign users thier default tablespace cause it was just huge!

The only piece of advice I would offer to you is to learn how to administer your conncurrent managers correctly. If you understand how they work and how to use them to your benifit it will save you a lot of headaces.