How many times have you visited a site and clicked on a link only to find it goes nowhere? How often do you check the links on your website to make sure they are still working? One of my favorite tools in the LinkChecker Addon available for the Firefox browser.
Susan Emerson is one of the instructors in the Web Development Training Class which is part of the free SEO Training offered by GNC Web Creations. She has a post on her blog Web Page Mistakes with solutions, titled about Find Broken Link.
There various tools available to find broken links on your own website. Some are free, some are browser plugins and some are part of a paid software package.