Answer by Jared ·
you should probably start by reading the upgrade documentation.
Since you did not supply any platform information, or which 11g (R1 or R2) I will assume R1, and point you to the documentation location.
Answer by HillbillyToad ·
I'd probably create a brand new instance of 11gR1, then create a full database export of your schemas in the 8 database, then import them into the 11g database. Upgrading from 8 to 11 wouldn't be very fun. You'll want to make sure your 8i hardware will even support the new 11g system. The number of processes, CPU, memory, IO demand of 11 compared to 8 may overwhelm your setup.