Have seen those sites with copy that is littered with hyperlinks? Over and over, the same words are linked, highlighted in blue and strewn throughout the text. Not only it is distracting to read this text, it proves fruitless to the site.
While the internal linking is beneficial to the page and the placement on the search engines is obviously a wonderful boon, if it annoys your users and they leave your site, it does you no good!
Having too many hyperlinks on a page is similar to a flash presentation -- the idea is to help the user, but in the end, it just diminishes the site's importance from an SEO perspective.
It is recommended that the maximum number of hyperlinks within your copy is 2 to 5. And please don't repeat your hyperlinks throughout the page. A little bit goes a long way when it comes to hyperlinks. You want the links to jump out at your customers.