Let's say I want to link to Bobby Jones, the right handed pitcher, and I create a link like so:
- [[Bobby Jones]]
My problem is, that link will lead not to Bobby Jones's page but to a disambiguation page that lists both the righty and lefty Bobby Jones. That's a pain because it won't be obvious to the reader which Jones you're talking about.
The page for the righty Jones is actually called "Bobby Jones (jonesbo03)" though that looks pretty clumsy if I use the whole title every time I link to it.
So my link to Jones the righty should take this form:
- [[Bobby Jones (jonesbo03)|Bobby Jones]]
The key item being that little | or "pipe" after the title of the page. What follows the pipe is what actually appears as the text of the link in your page.
So here's a way of getting to Bobby Jones, the righty.
And here's a way of getting to Bobby Jones, the lefty.
See also Disambiguation for a complete list of disambiguation pages.