I speak to groups about WordPress frequently—mainly at the East Bay WordPress Meetup. I love WordPress and I love teaching. You can find me answering questions at the Meetup on the third Sunday of every month at Tech Liminal in Oakland. We meet from 1-3 PM.
You can see my presentations (and those of guest presenters) on the EastBayWP.com website. (Some of them are also on my LinkedIn profile.) I normally use slides as a visual addition to a presentation, so the slides by themselves don’t usually provide a very complete recording of the event.
I wrote and recorded a series of twelve videos for Peachpit Press in 2011 as part of their Visual Quickstart series. In 2012 and 2013 I taught WordPress classes through Media Bistro. These experiences taught me not only how much I hate editing video (I handed that job off wherever possible), but also where newcomers to WordPress without a web design background get hung up. (Those with a background in HTML or in other content management systems tend to get hung up in different places.)
I also do individual WordPress training, both as part of development packages for clients, or for people who already have sites but need to know how to use them. In the course of this training I might record a live Google Hangout with screensharing, produce pre-recorded videos, or produce illustrated documentation. (I find it faster to read than to watch, myself, so prefer it unless video is an absolute requirement. PDF documents are also easier to search than videos.)
I will sometimes do one-on-one training for local clients in person.