My problem is that I want to be able to upgrade the pages on my Apache
server using FTP.

I have created an account intended to be utilized for upgrading pages and I
have defined the home directory of this account as the directory where
Apache stores the html-files. When I log on to the box using ftp I can list
and download the different files, but I can't upload any new stuff or
otherwise make changes.

My problem boils down to that I need to set the permissions for my account to allow writing stuff into the directory, but how do I do this ?
The account is set to belong to 'nogroup'

Thanks for advice !

Welcome to LQ.

if your user is in "nogroup" tehn you should be able to chgrp the folder to "nogroup" then make sure the group has write access with a "chmod +g folder". For more information look at:
http://wiki.linuxquestions.org/wiki/Permissions

Thanks, I had forgotten to chmod the folder, things work now as they should.