I suggest that you look in the area where you are for any packaging training. Usually it is only for AdminStudio / InstallShield now-a-days, but if you are in Europe you could have a look at RayPack. Also, you need to learn about the Windows Installer technology before even thinking about trying to use any packaging / repackaging tools. Have a search here on the site. If my memory serves me correctly, a similar question was asked not too long ago.
You could start here..
Also, InstallSite provides some off-line books that are specifically for repackaging / preparing installations for mass deployment.
First be strong with windows Installer. Start with this book.
If you are using Installshield, press F1. The help guide will explain you everything in detail.
that's a good book, but a bit dry.
I deliver training on this. Here is one of the examples we do. On day two we play with Orca, Edit orca in orca. (we have already used Orca in day one, but that was using tools to capture an EXE install to create an MSI from scratch) now its time to get more into the tables.
Create a transform that only installs the first feature listed.
To do this you need to look in the Propertytable, locate the INSTALLLEVEL property. Then read the MSI.chm file (available with the same SDK download to get Orca) to figure out what you have to do in the feature table to turn of a feature so its not installed.
The we go a bit crazy and create 3 MSTs for different hypothetical departments. we also start looking at adding/removing shortcuts, basically getting used to the table structure.
When you have the MSI.chm, there is a section on Windows Installer Examples.
if you step thought that exercise, you will be well on your way to conquering the MSI side of things.