Maybe you are viewing the old pages from your browser's cache.
Try to force a browser refresh (CRTL + F5) and have a look if your changes are showing.
On the other hand, if you just made some minor change in the content of a page you only have to upload this page to the server.
I don't know what the publish structure of your project might be.
If you publish by Site Structure, which I would recommend for a better overlook, it's very easy.
Please read this tut of gotfusion for further explanations:
http://www.gotfusion.com/tutorials/tut.cfm?itemID=181
So if you made a minor change in one page, have a look into your Local Publish folder, select this specific page and upload it onto your server.
It's different if you made major changes, f.e. concerning the navigation by adding a new page, you will have to upload the whole project.