monitoring the performance of a High-Availability cluster

i need a step by step guide on the following:

1)how to set up a virtual High-Availability cluster on VMWare with Linux-based CentOS and openSUSE as operating systems using three nodes?

2)what do i use as criteria in measuring and monitoring the performance of a virtual High-Availability cluster?

3)what are Ganglia and Nagios exactly? and how do i use them in monitoring the performance of a virtual High-Availability cluster?

4)where can i specific information on virtual High-Availabilty cluster?