Enabling refToolbar
  1. In my preferences, click the Editing tab
  2. Click to select the Show edit toolbar (JavaScript) check box
  3. Click Save
  4. In the Gadgets tab, click to select the refTools check box.
  5. Click Save

This brings up the editing toolbar below:

There you will see this button: (Insert citation)

Adding citations
  1. Click the location in your text where you want the citation to appear.
  2. Click the Insert citation button, and then select the button that best describes the reference type: Web, News etc. Add the details in the relevant fields, and then click Add citation.
    Note: Ensure you add a Reference name:, so that you can reuse the reference later.
  3. If you want to reuse a previously added reference, click the Named references button. For best use of named references, make sure you edit the entire page instead of a section.
    Tip: You can add the date in the ISO 8601 format YYYY-MM-DD eg [[2008-11-16]]

Note that the title, publisher, named reference, URL, and author (if available) are important.