I receive this question (how can I start on apps technical filed? How can I be an apps dba?...etc)
Well I am going to give some hints from my point of view, those hint may not be the ideal therefore any reader of this post can leave any suggestions to make the steps better and easier.
-First of all you need to have instance (vision demo database) so you can test things on it, by this I mean that you should read the installation guide which will guide you on how to build the stage area and what are the pre-requisites (hardware/software) for the installation and the installation process using rapidwiz
The installation will not finish successfully form the first time unless you are so lucky, and from the installation you will get a good experience.
-after the installation you need to understand the applications file system structure.
- also you have to read oracle applications concepts guide.
Then you can start reading about applications administration and maintaining procedures, you need to understand both adpatch and adadmin.
- By now if you manage to install oracle applications and to apply patches on it then you are in the right track.
-then after that you need to read about backup and recovery.
-you need also to monitor oracle forums and oracle blogs.
-keep metalink as your friend.
-when you see an interesting issue in forum or blog try to track it and maybe try to solve it if you can this will give you an add experience.
-try to participate on oracle applications email lists like ittoolbox …etc.
-try to get oracle applications administration books like dba filed guide and others.
finaly keep in mind that (no pain no gain)
Please leave comments on what you think the best way to be an apps dba
P.S all the guides mentioned above can be found under (for apps 11i) http://download-east.oracle.com/docs/cd/B25516_16/current/html/docset.html