Question: I have a Ubuntu VirtualBox host and two Ubuntu guests. I need to be able to ssh into both guests and be able to ssh to/from guest1 and guest2.

I'm really stuck. I've tried NAT settings, bridged adapters and host-only adapters.

All I want is for each guest to have its own IP address (e.g. guest1=192.168.56.101 and guest2=192.168.56.102).

Is this possible?

Answer: 
I am currently running an Ubuntu server (with Gnome installed) running a Windows Server 2003 Active Directory as virtual box host and runs no problem using a bridged connection. The host is on 192.168.1.31 and the guest is on 192.68.1.32. Are you even able ping either of the guest computers from another computer other than the host???
Apparently, I didn't have ssh-server installed. Installing it fixed my issue.