- yum install bzip2 kernel-devel gcc make perl
- click 'insert Guest Additions CD Image ...' from VirtualBox Manager's Devices menu;
- mount /dev/cdrom /mnt
- cd /mnt
- ./VBoxLinuxAdditions.run
- reboot
- add a shared folder, say 'temp', to the guest from VirtualBox Manager's Devices menu;
- mount -t vboxsf temp /mnt