Apps 11i DBA preparation

As part of your Oracle Apps DBA training will include
roles & responsibilities of oracle Apps DBA.

1. Apps Architecture 
This is key topic & you should be very clear about Oracle Applications/E-Business Suite
11i components & Architecture. This is base of your knowledge & if you are not clear about
various components & uses it will be quite difficult in learning Apps.
Where to find Oracle Applications 11i architecture in Ocean of oracle Application
technical documentation. Well I agree with you go straight to http://download-uk.oracle.com/docs/cd/B25516_08/current/acrobat/11iconcepts.pdf and go through chapter 1 (Page 13 to Page 32 Just 20 Pages)

2. Installing Apps 11i
Next point in apps dba training is Oracle Apps 11i Install using Rapid Install preferably on Linux/Unix
Where to find Rapid Install 11i Oracle Apps Guide This is guide by Oracle http://download-uk.oracle.com/docs/cd/B25516_08/current/acrobat/r115102ins.pdf for a start Chapter 1 & 2 are enough page 13 to p 63 is enough to understand Installation)
Where to find Discs / software for Oracle Apps 11i E-Business Suite : You can download it via http://edelivery.oracle.com or order it via your Metalink account . Once you got CD , please do install Apps atleast once in order to understand & to familiarize your self with Oracle Applications

3. Apps 11i File System/Software 
Once you installed applications 11i using above guide on Unix/Windows/Linux software then login as Operating System User & check directories while going through document
http://download-uk.oracle.com/docs/cd/B25516_08/current/acrobat/11iconcepts.pdf Chapter 2 Applications File System (P39- 48) very important in understanding Database Server & Application Server Tier & various tops like DATA_TOP, ORA_TOP, APPL_TOP, COMN_TOP, AD_TOP....
If you know your applications 11i File system you know where to find particular component files & logs .