YouTube - SourcefireInc's Channel.
TheAcademyPro does some wonderful videos for us showing some of the aspects of the Sourcefire interface, working with Virtual Machines, just showing how easy it is to navigate around the Sourcefire interface. If you read my blog and you are a Sourcefire customer, or just a plain Snort user who is interested to see how things work within Sourcefire, check out these videos.
There are a ton of videos in there, how to manage policy, make remediation alerts, etc. Covering a bunch of different aspects of the Sourcefire interface. Check it out!