Hi Chris
For the versions of Oracle DB , which you can directly go to Oracle 11G , in 9i , it needs to be minimum 9.2.0.8 and in oracle 10g R2 , it needs to be 10.2.0.2 ...
Please see the following oracle documentation which is detailing about the steps and options for the upgrade - mainly DBUA , manual steps and also the export import facility .
Preparing to Upgrade Oracle Database
Export / Import using the Oracle Data Pump is generally recommended for 10g databases which are being migrated to 11g.
Thanks
Rishi
