Quick Guide on how to install Reporting Services on its own server/cluster in SharePoint Integration Mode without using Kerberos

1. Install SQL Server 2005 - Reporting Services Only
2. Install SQL Server Service Pack 2
3. Install Sharepoint (as WFE)- SKU (Enterprise Edition, Standard,etc..) has to match the other SKUs in the farm
4. Run the Sharepoint Server Configuration (do not add central admin unless you want to) - Not sure if this step is needed but can't hurt
5. Install the reporting services add-in for sharepoint
6. Run the Reporting Services Configuration Utility [start-->all programs-->microsoft sql server-->configuration-->reporting services configuration]
7. Create the ReportServer Virtual Directory (ReportServer) preferably
8. ReportServer AppPool and Reporting Services Windows Service should both be a domain account
9. Create the Database (create the database in Sharepoint integration mode) -
10. (Here's the Trick) - the Website that contains the report server vdir attempts to negotiate authentication by default.  This is not needed if you are not configuring kerberos. 
11. To fix this if you do not intend to use kerberos, open a command prompt, cd to c:\inetpub\adminscripts\
12. First check to see if there is an authentication provider run cscript "adsutil.vbs get w3svc/{WebSiteId}/root/NTAuthenticationProvider" ({WebSiteId} being the id for the website containing the RS Vdir), this should return [The parameter "NTAuthenticationProviders" is not set at this node.]
13. Then run [cscript adsutil.vbs set w3svc/1/root/NTAuthenticationProviders "NTLM"]
14. This should return [NTAuthenticationProviders       : (STRING) "NTLM"]
15. Next go to Sharepoint central administration and enable the reporting services feature and then configure the rest of reporting services within application management.  Be sure to set the authentication method to Trusted Account. 
16. For more information on this see - http://blogs.msdn.com/sharepoint/attachment/4194088.ashx