You've left outer some very important information -- what is the OS running on the PC's? What version of Netware is running?. Are you connection to the server using IP or IPX? What network client software is being used on the PC's?
But, some general answers:
1) yes. and maybe -- it's certainly not too hard
2) If you are using Windows 2000 Pro, or XP/Pro, once you have the new NIC installed, simply go to the network connection properties and make sure the Novell Netware client is bound to the card
3) Very easy --load the drivers, and bind a network address to it. More specific instructions can come when we see more details about your network
4) no
5 Absolutely