Hi, welcome to the ranch!
Your topic hit the nail on the head - content management. Content management systems are a pretty lively area. Have you read up on some commercial or open source solutions to see how they work? You may want to copy some of their ideas, or just use a proven product. See the
list of vendors evaluated here.
One solution would be "dynamic" content of some kind, maybe coming from a database and building HTML on the fly. Another might be an FTP or application upload feature to let somebody post new files.
Your problem sounds familiar. A decade ago I worked on a Fortune 50 corporate web site that had a legal document number on most or all pages. LDs had an expiration date right in on the page. Every week or so, invariably about 4:00 on a Friday, the legal dept would call and say "These pages are out of date, remove them from the site IMMEDIATELY!" and we'd madly pull pages and change links, editing on a live site. Bad Gnus. Now the site is run under a big time CMS that has workflows built in to remind somebody to refresh the LDs a couple weeks before they expire.