There's a rather useful page of ARM installation instructions at https://fedoraproject.org/wiki/Architectures/ARM/F20/Installation which explains what image to download and what installation process to use on each supported ARM platform. The ARM download page - https://fedoraproject.org/get-prerelease#arm - should probably link to it.
Fixed in rev #439793b I just added a link to the install procedure. Please check after next build (in about 1h30) and reopen if you think it needs to be improved.
Thanks!