Here is a dedicated site (not on the oracle.com domain). Here is the home page on OTN.
Maybe it's just me, but I've read or heard virtually nothing about this release. That's pretty amazing. I remember reading about 10g prior to release...I can't remember 11gR1 though. I'd have to say that's a pretty impressive feat.
At the first site, there is an Eduquiz which, after you submit your answer, links to specific areas.
Lower Costs with Oracle Database 11g
Security and Compliance
Documentation can be found here and New Features can be found here. I guess I'll be reading these for fun and enjoyment tonight.