Zend certified PHP/Magento developer

How can a webpage or web server prompt that a browser recache a page?

I’m updating a website that’s just gone live and am trying to work out a way to ensure that all users see the change reflected on pages – I’ve found that the only surefire way to get changes to be reflected is to have the user force reload the page, and it wouldn’t be suitable in my eyes to continuously change the address – is there any way, either through the HTML content or the webserver, to force a page to be reloaded from cache on the next reload by a user?