Basic info for a cluster.

Pay attention to "where am I"… so you know if you are in the right node.

/*
Basic Cluster Info
*/
DECLARE @name AS VARCHAR(40)

SELECT @name=COALESCE(@name,'') + ' ; ' + Nodename
FROM ::fn_virtualservernodes()

SELECT
 SERVERPROPERTY('isclustered')	 'Is Cluster?'
,SUBSTRING(@name,4,len(@name))	 'NodesOFCluster'
,SERVERPROPERTY('ComputerNamePhysicalNetBIOS')	  'ActiveNode'
,HOST_NAME()			 'where am I?'
,SERVERPROPERTY('ServerName')	 'SQLServerName'
,COALESCE(SERVERPROPERTY('InstanceName'),'DEFAULT') 'InstanceName'

Example

Here we have a THREE nodes cluster, and SQL is running on Server B.  We are running our SSMS on ServerC.