To install Plesk on a number of servers, you may want to set up a mirror of the official Plesk update server (http://autoinstall.plesk.com) inside your network so as not to download the distribution files through the Internet each time, and then install Plesk as described in the Installing Plesk Remotely on a Number of Servers section.
If you do not want to set up a mirror, you can skip the Setting Up Mirrors section and go on to the Installing Plesk Remotely on a Number of Servers section.