u might want to consider a router if you have broadband if not don't use DHCP try static and make sure you have SAMBA - you can get more info on it by going to
www.google.com and type in Samba or try the man pages.
If you decide to keep DHCP still I would use a router to help both boxes although it is concivable to setup Linux as a router but until you get comfortable with Linux I would not advise.
Linuxs rocks but you will have to learn to think different...