1. Select the text you would like to link.
2. Click on the link button (the chain link icon)
3. Fill in the url (web address) you would like to link to.
4. Select the target (you can choose if you want the link to open in the same window or pop up in a new window when the link is clicked). Do not make it pop up if it's a link to a page on your own website (people hate that). Only use this feature for links to other websites.
5. Link Title is optional. This is a description of the link.
6. Leave the Class as - Not set - (i.e., do not touch it)