The HTML for a clikable link (hyperlink) is
<a href="target site URL">anchor text</a>:
where anchor text is whatever what you should type in which you want displayed (seen) on the web (if unfamiliar with URL, see What is URL and how to get it). For example, this HTML
<a href="http://foodasmedicine.blogspot.com" target="new">Natural Remedies</a>
will result in the following clickable link as seen below which when clicked open the target site in a new window:
I have added the attribute target="new". Some also use target="_blank" but the first one you don't need to press the shift key and is shorter. Please note that both has been deprecated and is on the way out with the XHTML (strict) coming into force. However, both will still been supported by XHTML (transitional) for a long while more.
The anchor text is important to search engines because it tells what the target site is all about and you should use something relevant/descriptive of the site for the target site. Don't ever use
<a href="target site URL">herelt;/a>:
as it tells nothing about the target site, and is useless for telling search engines what that target site is all about.