I recently migrated my windows 2003SBS to a windows 2008 standard server. The server has two network cards and has the DHCP DNS and AD roles. On the old SBS machine there was a wizard that helped nicely to configure one NIC as the internet gateway and the other to connect the clients. Now I am on my own and failing...  

The server can access the internet, the clients can logon to the domain and browse one another's shared files, but the clients have no internet access.
How must I configure this?