Allows easy access to all of your posts, to reference while writing.
Simply highlight the text you want to be the link text, and then click one of the links 
in the WP Site Links box, and the link will be created.

WP Site Links

Allows easy access to all of your posts, to reference while writing.

piffpaffpuff

Related Links gives you the possibility to manually link other posts to your current post. But you can also link pages, media or any custom post-type. And in addition you can use custom urls to link to external files. The plugin adds a Metabox to the writing page with a list of all available content.
Features:
<ul>
<li>Shows a list of all available content in a Metabox on the writing page</li>
<li>Multiple links can be selected</li>
<li>Link order can be changed through drag and drop</li>
<li>Custom URLs can be added</li>
<li>Search field to quickly find a link</li>
<li>Simple theme integration with an included widget or <code>related_links()</code></li>
<li>Works with custom post-types</li>
<li>Settings to enable the post-types that should be shown in the Metabox</li>
</ul>

WP Site Links vs Related Links