This information will help them find new material easily. You may also want to indicate new content on a particular page with graphical cues.
Dead links frustrate users.
Check all of your links periodically and correct or remove the ones that are no longer working. The tracking report generated by your server software can tell you the location of broken links. Maintain the naming and file directory system you established during the original development of the site. Continue to back up your files and store them safely. Document your procedures for naming and structuring files so others can learn your system easily.