WordPress have a great Support section, and this is clearly the way for most people. However I was producing a tip-sheet for my sister-in-law and thought this may be useful to others as well.
It includes the following sections:
1. Settings – basics for setting up your WordPress site
2. Appearance – as above
3. Pages – creating and editing pages (HTML Editor)
4. Posting – as above
5. Media – adding media files
6. Users – some considerations before adding users to your site