How to get start work with Reporting Services in Sharepoint Server 2007

Hi all,

I am working in MOSS 2007 and want to know how to start working with reporting services in Sharepoint Server 2007..

What are all the System Requirement & Basic Steps to be taken for enabling the Reporting Services.i got some information through

Google that we need to install SQL Server service pack2 for this service & Installed that one too..

Then i run,

Microsoft SQL Server 2005 -> Configuration Tools -> Reporting Services Configuration. -> Databse Setup ..

Then i tried to change the Database Server Mode from " Native " to " Sharepoint Integrated Mode "

when i press Apply button, Receiving the Follwing Error..

" (*) There was a failure applying your change.

A virtual directory must first be created before performing this operation. "

Please let me know , if someone is working on this..

Regards,

Suresh.