How and Why to Find and Remove Broken Links
Broken links can be SEO death for a website. They give crawlers a dead end and make your site appear less relevant and up-to-date. In addition, they frustrate people who are using your website and increase the chances that they will leave and never come back. Unfortunately, it is easy to accumulate these, whether from typing in an address wrong or from the site you are linking to changing their URL without a redirect.
There are several plug-ins and webmaster tools for finding broken links. However, the easiest way uses Google Webmaster Tools. Go to Diagnostics and click on Crawl Errors, then Not Found. View the pages with broken links and fix or change them.