Training a new partner to maintain an existing site

I manage an existing site (see here) and within my organisation I want to train up a partner to share the editorial load of maintaining it. Can anyone suggest a suitable tutorial (written or video) that I could use or adapt to help me introduce people to what is involved. My target partners are unfamiliar with WordPress or any blogging or website creation programs but have basic computer skills. Existing tutorials spend a lot of time on registering and initial setup which of course in my case is unnecessary. – Many thanks.