Step 2) Boot up your virtual machine, and add the following line to the file: /etc/rc.local
mount -t vboxsf -o uid=USER_OWNER,gid=GROUP_OWNER SHARE_NAME MOUNT_DIRECTORY
USER_OWNER is the owner of the mounted folder. This will give the owner full read and write access.
GROUP_OWNER is the group owner of the mounted folder. The group will have read and write access.
SHARE_NAME is name of the virtual box share name.
MOUNT_DIRECTORY is the mount point of the share.
Example: mount -t vboxsf -o uid=john,gid=john VBoxShare /home/john/VBoxShare
Voilla! Easy file sharing from your host operating system and the Linux client.