Windows 2008 failover cluster
A failover cluster is a group of independent computers that work together to increase the availability of applications and services. The clustered servers (called nodes) are connected by physical cables and by software. If one of the cluster nodes fails, another node begins to provide service (a process known as failover). Users experience a minimum of disruptions in service.
Before begin , need to have a domain account for service to manage on different nodes and all the servers are added to domain. You need to have running failover cluster running on all the servers before you add the nodes. Also have need same hardware, software, accounts, and network infrastructure.
This document is a 2 node majority node quorum configuration