Internal linking is very important. First of all, it's easier for your visitors to use the site. It also tells the search engine which page on your site that a special keyword. But don't link to much 1-3 link of 500 words will be ok. And the text on the page must of course be relevant for the keyword.
50 internal links is really a huge number..make it to a reasonable number..may be 2 or 3 links per page.