Remove the welcome page:
cp /etc/httpd/conf.d/welcome.conf /etc/httpd/conf.d/welcome.conf.bak
sed -i 's/^/#&/g' /etc/httpd/conf.d/welcome.conf

Stop Apache listing files:
cp /etc/httpd/conf/httpd.conf /etc/httpd/conf/httpd.conf.bak
sed -i "s/Options Indexes FollowSymLinks/Options FollowSymLinks/" /etc/httpd/conf/httpd.conf


Reboot.