By default, the web profile page pulls the automatically named "Personal Website" and "Research Website" fields from Activity Insight (located under General Information -> Personal & Contact Information).
If you'd like additional links, log in to Activity Insight and visit the "Web Profile" screen under General Information. Look for the panel titled "Additional Web Link":
You may add up to three additional links, each with a custom title. Note that your faculty web profile updates every 24 hours, so you will not see your changes until the next day.