I’ve read the automatic installation documentation but I am afraid that I was not able to figure out the steps to do the automatic installation on my VPS, which using CentOS 6 32x.
Please help!
You can download the automated install.sh script using the “Download” link above.
The basic instructions are all available in that link.
Those basic instructions are normally enough to get things up and running.
More instructions are available here:
https://www.virtualmin.com/documentation/installation/automated
you should get the script with wget cmd. $ is your shell and so you can copy & paste what I have after it. You should be logged in as root to do this.
$ wget http://software.virtualmin.com/gpl/scripts/install.sh
$ chmod +x install.sh
$ ./install.sh
then wait till the script finishes running. After that you can log in via the browser.
If any problems arise, please attach the log files (install.log found in the same directory as where you were installing from)
It is running now
Thanks a lot 
Ok, how to really started to go through the documentation?
I started by get started part, but really feel confused a lot.
I think I should start by adding a new domain or new server, but where to know details?
Also, it says :"1024 MB total, 665.82 MB used ".
Is this ok to have 60% used?
I wouldn’t worry about your memory usage unless you start running out of it.
As far as how to get started – just add a domain. You can do that by clicking “Create Virtual Server”. In that screen, you would just put the domain name you’re adding in that screen.
-Eric
I also recommend familiarizing yourself with the configuration, templates and other settings of VM. Just click through all functions basically.