[banden]

ronaldheld,

'Rooting' in and of itself is only a permission. It's similar to getting administrator access to a PC.

Before you root, you really don't have any options to back up your system outside of saving APK files and storing your information on external/removable media. HOWEVER, once you do root, the first thing you should do is install the nandroid recovery software, and perform a full backup before you go playing with anything. This is an image of the current state of your system including desktop/widget state as well as all installed apps and their settings.

So, to answer your question, you should install nandroid and backup your system as a first step AFTER rooting your phone. Might be a good idea to store a copy of that backup externally too.