Hi, and welcome to LQ!
Have you tried your internet with the new card?
Typically, Linux has it's own drivers, and should detect the new card on startup. (In fact, there are only two video card OEMs that require drivers to be installed seperately.)
If Ubuntu does not auto-detect the card, reboot and press ESC when you see "Grub loading..." to enter the Grub menu. Select "Recovery Mode", then when the new menu pops up, select "Detect Hardware".
And no, wireless wouldn't be easier. That's something that's still a bit questionable. It's wonderful if it works, but a RPITA if it doesn't.
Hope this helps.
Last edited by DragonSlayer48DX; 04-04-2009 at 12:22 PM.