My wife and I have a fairly large website (3000+ pages) with tons of images, etc. All pages are html. My wife started our site 6.5 years ago and is self taught through forums and the like. Since starting to help her more this year, I have noticed that we seem to lack cache control. When updating a page, a viewer must refresh to see any changes, even if the changes were made the previous day.
What is the best practice in forcing a refresh on our older pages when they have changed, without forcing a refresh on existing images (worried about load times, bandwidth, etc that could be problems if forcing everything to refresh)?
Our site is
http://www.legendsofamerica.com