SQL Server 2008 Cluster Installation Steps:

Installation step by step of SQL Server 2008 clustering on Windows 2008 

    Step 1 : Validation wizard
    Step 2 : Pre-check
    Step 3 : Installation of the first node
    Step 4 : Add a new node 
    Step 5: Apply a service pack or hotfix on a SQL cluster 

http://blogs.technet.com/b/mdegre/archive/2009/12/25/installation-of-sql-server-2008-clusters-on-windows-2008-step-1-validation-validation-wizard.aspx

Other links

http://www.mssqltips.com/sqlservertip/1687/install-sql-server-2008-on-a-windows-server-2008-cluster-part-1/

http://clusteringformeremortals.com/2009/10/07/step-by-step-configuring-a-2-node-multi-site-cluster-on-windows-server-2008-r2-%E2%80%93-part-3/

http://dusk1911.wordpress.com/2011/06/12/installing-sql-2008-r2-cluster-step-by-step/

http://www.databasejournal.com/features/mssql/article.php/3783326/Installing-a-Two-node-SQL-Server-2008-Cluster---Advanced-option.htm