To insert a link, use the <a> tag with the href attribute to indicate the address of the target page. Example: <a href="http://www.google.com"> . You can make a link to another page in your website simply by writing the file name: <a href="page2.html"> . Links can also be used to jump to other places on the same page.
Well its very simple. You need to have basic knowledge of HTML to be able to do this.
You can Google it for Ahref tag and BB Code there you will get idea how to link any word or phrase to a website.
Sometime you can create a link by selecting a word or phrase and put the URL you want to link to by clicking link symbol.