New Tomtom, now what to do first?

Connect to computer and do a full backup of device contents!
This is a crucial step wich you should not ignore.

DO NOT use Tomtom Home software to do this, do it manually from within Explorer or similar for MAC. Make sure all hidden/system files are visible when you do this.

Keep this backup in a safe place, a good idea is to burn the backup onto a CD/DVD.

The most important part to have backed up, is your map folder(s).
This is where the license part of Tomtom comes in, the software is free, maps aren't...