1) Navigate to the page you'd like to add a link.

2) Ensure that you're in the Edit mode of that page.

3) Highlight the title or portion of text you'd like to link to another page.

4) Click on the link icon which will bring up a field to either enter the title of a new page or title which matches existing pages from within your account.

5) Ensure that you click the check icon to Save your changes.