Application Manager has a default set of apps and you most likely want to add
some more.
As root, go to /etc/dt/appconfig/appmanager/C
'C' is default English, if you use another, go to the respective language
folder.
Make directories for Internet, Games, Accessories, Video_and_Sound or any
other folders you like.
Copy from /home/user/ all folder Actions you want to see in these respective
folders.
You must have created launchers called 'Actions' first with the 'Create
Action' app. Actions are launchers with icons for Iceweasel, VLC and any
other apps you may have installed. You can drag and drop these Actions to
your Front Panel menu for easy access.