Hello,
1. For partition sizes, you can either follow Advanced Options: Pre-Installation or Quick Start Installation Guide for the recommended partition sizes. The first is advanced partitioning, while the second is basic partitioning.
2. The cPanel installation process itself is simply:
Code:
cd /home
wget -N http://httpupdate.cpanel.net/latest
sh latest
After that, you would load http://IP#:2087 in a browser where IP# is the IP address for the machine, then go through the initial startup wizard in WHM.
3. This question is simply too broad to provide adequate responses. If you narrow down to more specific questions, we'd be happy to help on those specific questions.
4. If you have set cPanel questions, this forum would be best for those questions. If you have questions on any specific software being used like WordPress or Joomla on those customer sites, the software makers' respective forums would be the best location.
Thanks!