In terminal, use the following code to set the file and folder permissions:
chown www-data:www-data -R * # Let apache be owner find . -type d -exec chmod 755 {} \; # Change directory permissions rwxr-xr-x find . -type f -exec chmod 644 {} \; # Change file permissions rw-r--r--
source: http://stackoverflow.com/questions/18352682/correct-file-permissions-for-wordpress