The Importance of Internal Links
No website is ever complete without linking from within your own pages to your other pages, and not through your normal navigation, but from linking to your other pages from within paragraphs. Google and other major search engines like to see relevant links to your pages, and if you link from one of your pages to another of your pages, their algorithm is tuned to see this as highly relevant, especially if you use good anchor text to link to your other page.