How to install Linux guest additions
Display issues with KDE in VirtualBox
Setting display resolution of VirtualBox window
Shared folders in VirtualBox
VirtualBox host-only networking for sharing guest folders with host.
Installing Guest Additions for openSUSE guest.
Installing Guest additions in Zenwalk manually, by extracting files and editing routines.sh.
Repository of VirtualBox Guest Additions for openSuse
Tutorial for installing CentOS under Virtualbox
Auto-mount VirtualBox shared folders via "/etc/rc.local".
Official documentation for installing Lubuntu Mini.