You must switch to HTML mode in order to add HTML. Most text editors are in WYSIWYG mode. However, they usually have the option to work in HTML mode as well.
In Hubpages try this:
* Go to a Hub and open a text module
* On the left side of the text module right above where you enter the text you will see "HTML"
* Click the "HTML" mode
* Insert your HTML code
* click save
If you are working in the link capsule, you dont need to insert HTML. Just insert the website address starting with http://