For the visual learners in the crowd, I thought I'd let you know there's now a comprehensive OmniFocus video training course available from Lynda.com. The training course offers more than 3 hours of info, but it's broken up into manageable 5-10 minute videos for your viewing pleasure. (I don't know about you, but the idea of sitting down to three and a half hours of anything is enough to send me packing. This is why I avoid all movies described as "epic" or "a sweeping cinematic masterpiece", because you totally know that's just shorthand for "better not drink anything before trying to watch this, unless your bladder is the size of an Airstream").
You'll need a Lynda.com subscription to watch the entire course, but there are a number of videos available for free so you can check out their approach and decide if it seems up your alley.
From the course description:
Join Chris Mattia in OmniFocus Essential Training as he shares how to capture and organize projects and action items into a system for managing tasks and getting work done. This course covers working with projects and contexts, dynamically building to-do lists, creating custom views with Perspectives, and synchronizing the OmniFocus database across multiple computers. Exercise files are included with the course.
The philosophy behind OmniFocus
Creating an actions list
Organizing projects with folders and action groups
Scheduling parallel and sequential actions
Adding photos and audio to actions
Integrating with iCal and Mail
Backing up and exporting data
Using the OmniFocus iPhone app
Also, don't forget—there's an online training course for OmniGraffle, too. There! I just planned out your whole weekend for you. It's gonna be awesome.