Re getting the internet to work. One thing which isn't well documented,
is that after you've altered the settings for the network, you need to
dissable the interface, usually eth0. In network/connections you should
find a small box (in 7.04) for unchecking this. Exit all the menus.
Then enable eth0. I've had a lot of problems, before discovering this
feature!

I haven't had any success with DHCP, and prefer to use static IP adresses.

Can you ping your modem or router? That's one of the first things to try.