[ubuntu] How to access shared folders in Virtualbox Ubuntu VM?

I have installed the latest version of VirtualBox with the Extensions under 12.04. I've created an Ubuntu 12.04 LTS VM. I then created shared folders from my non-VM Ubuntu. The shared directory is persistent.

However, I've no idea how to access the shared folders on the VM. I've done this in Windows VMs but cannot do it in Ubuntu VM.

I've read a number of guides which talk about the vboxusers group and suchlike. I've tried it all but cannot see the shared folder in the Ubuntu VM.

So, my question is: how would you go about accessing the shared folder in an Ubuntu VM?

Thanks.