You can cite your text sources by clicking on the "Wikitext" button, then using the following format:
The Sun is pretty big,<ref>Miller, E: "The Sun", page 23. Academic Press, 2005</ref>
but the Moon is not so big.<ref>Brown, R: "Size of the Moon", ''Scientific American'', 51(78):46</ref>
== Notes ==
<references/>
This will be the result:
The Sun is pretty big,[1] but the Moon is not so big.[2]
You can also use the <R> button on the editor when you are not in Wikitext mode to create a source, but then you still have to use the Wikitext button to enter "<references/>" at the end of the page.
In addition, when uploading files using the "Upload file" link from the Toolbox links at the left, always choose a License from the Licensing drop-down.