Though writing is core to blogging, you don't have to be a professional writer. Correct spelling and grammar should still be observed though. Best practices recommend to write at least something everyday, even if it isn't published. Also recommended is to have someone else review the article before publishing.
Another option is to either do a video (YouTube) or podcast (iTunes, SoundCloud) and embed it along with a transcript of the media. In doing this, you can actually expand the reach of the content because it exists on two different platforms.