Thanks Till and Falko..
I've read the doc, and also print it and put it near my screen
The reason why I was in doubt is that:
It is recommended to use a clean (fresh) Ubuntu 8.04 LTS install where you selected no additional packages or servers during setup. Then follow the steps below to setup your server with ISPConfig 3:
Almost everything is going well.
I've just a problem with prewikka, because i've seen its index instead of the webpage...