This is one of the most fundamental things that needs to be done in any webpage.
Composer tends to handle most text formatting just like a word processor.
A hyperlink is like a button that takes you to another place, such as another page or a different part of the same page. First hit the link button on Composer's toolbar. To do this hit the image button. There are many options to format your picture, such as controlling this size. If you want your image to be a background just click the box labeled Use as backgroud You can even make your image a link to another page or site.