How to set up a private cloud using opennebula

I would like to set up a private cloud using 3 desktop machines using opennebula (or openstack) cloud platform. One will be the front-end and 2 nodes.

But i don’t have idea how can i configure/connect these machines (in terms of hardware) together to build that cloud environment.

I would like to know how can i realize this configuration to obtain/build my own private cloud and what are the steps?