so to mount an iso from the command line you would use the command
mount -oloop /root/CentOS-6.2-x86_64-bin-DVD1.iso /var/www/html/repo/CentOS-6.2-x86_64/
but if you wanted that to be mounted at boot time via your fstab. it is different
you would have to edit your fstab and add in a line similar to :
/root/CentOS-6.2-x86_64-bin-DVD1.iso /var/www/html/repo/CentOS-6.2-x86_64/ iso9660 loop,ro,auto 0 0
and then issue the command
mount -a
and finally verify with
mount