This could you help you to understand the setup and process.
http://msdn.microsoft.com/en-us/library/ms146922(v=sql.90).aspx
http://msdn.microsoft.com/en-us/library/ms151196.aspx
Some more information from external blog - http://sqlphilomath.wordpress.com/2011/08/07/how-to-configure-transactional-replication-with-updatable-subscriptions-step-by-step/
NOTE : http://msdn.microsoft.com/en-us/library/ms143550%28v=SQL.110%29.aspx
Cheers,
- Win
"Dont Judge a Book by its Cover"