I see all kinds of great and wonderful comments and answers here - too many to try to thank y'll individually - so I'm just going to say I like everything I've seen here and hope y'all will forgive me for not mentioning everyone by name!!!
I am not going to address anything about the correct genealogical aspects of citing sources - please understand that the ONLY thing I'm going to talk about is the techy end of HOW to do things - if these things are not academically correct, that's for you to figure out - sorry, but I don't know much about this end of it.
OK - I'm ready to dig into all this with some suggestions about how the sources can be coded. This will apply to two different situations - (1) when different pages (or places) in the same document are being cited in one profile and (2) when multiple profiles will cite the same document.
1. If you have a profile that states a fact that is supported by what is on page 4 of TheDocument and also states a fact that is supported by what is on page 17 of TheDocument and maybe also states a fact that is supported by what is on page 83 of TheDocument, if you want it to look like:
Biography
This is the story of the life of John Doe, who was born January 1, 1900(superscript 1 here). John liked to play with toy airplanes when he was a child.(superscript 2 here). When Joh grew up, he became a pilot and flew planes.(superscript 3 here).
Sources
1. TheDocument, page 4
2. TheDocument, page 17
3. TheDocument, page 83
* TheDocument, by Jane Doe, FlyByNight Publisher, January 1, 2000, (accessed January 2, 2000). (or whatever the source citation should look like - that's not my bag)
When you click on any of the superscript numbers in the biography, you will jump to the footnote under Sources. When you click on the link to MyDocument in any of the numbered footnotes, you will jump to the bullet item that has the full citation of the document.
Here is what the editing page would like like:
==Biography==
This is the story of the life of John Doe, who was born January 1, 1900.<ref name="page4">
[[#document1|TheDocument]], page 4.
</ref>
John liked to play with toy airplanes when he was a child.<ref name="page 17">[[#document2|TheDocument]], page 17.
</ref>
When John grew up he became a pilot and flew planes.<ref name="page83">
[[#document3|TheDocument}}, page 83.
</ref>
==Sources==
<references />
* TheDocument, by Jane Doe, FlyByNight Publisher, January 1, 2000, (accessed January 2, 2000).
Please note that I gave each <ref> tag a name attribute. That is not necessary - I just like to do it all the time because it makes it easy for me to identify what the source is just by looking at the name of the tag plus if I refer to the same source multiple times in the biography, I can use the <ref name="something"> tag the first time, with all the information about the source, ending with </ref> and for each subsequent time I only have to use the same name in a single tag of <ref name="something" />.
This is getting long, so I will write a comment after it to present how to do it using Space pages.