If you do not know how to create l;inks in posts or pages please read what follows.
All support documentation is found here http://support.wordpress.com
This is the guide for creating links in posts and pages: http://en.support.wordpress.com/links/
This is the general link model:
<a href="URL HERE">Highlighted anchor text here</a>
This is the visual result - it's not actually linked.
Highlighted anchor text here
1. Enter the anchor text you want to link to first.
2. Then use your mouse to highlight that anchor text. (If you don't highlight the anchor text the chain icon will remain grayed out and not be useable.)
3. Next click the chain icon in the editor and proceed to create the link.
More here > http://onecoolsitebloggingtips.com/2013/05/20/creating-html-hyperlinks-links-in-wordpress/