I have a VirtualBox image of win-xp, need to let it connect to the internet. The host is Ubuntu 64bit. What are the necessary steps I should take?
If you install XP on VBox with the deafult settings (AMD/PCNet III, iirc) and then install the guest additions it should connect to internet.
Open the Sun VirtualBox console and highlight the OS in question (the virtual machine you want to edit must not be running!).
In 'Details' open the Network properties, make sure at least 1 virtual adapter is enabled (checkbox), from the 1 drop down menu, pick the adapter model (PCNet-Fast III should be default and XP should automatically install this driver) and the 2nd drop down by default says 'Attached to: NAT'.
Boot Windows XP and check if a network adapter is installed in the Device Manger
If you choose the Intel Pro 1000 series adapter, you can download the driver for your OS here.
Under the settings for the VM, you'll have to change the network configuration.
Set it to bridged if you want it to appear as it's own node to other nodes on the network while sharing your internet connection.
Set it to NAT if you don't want it to be visible as another node, but still share the connection.
The only option that won't allow you internet access is host only.