you'll need to find out what driver your network hardware takes, and then if it isn't loaded, load it with:
#modprobe <driver name>
once that's loaded, or if it already is loaded, bring up your ethernet interface:
#ifconfig eth0 up
then you might need to get dhcp going:
#dhcpcd eth0
then see if you have an internet connection:
#ping google.com
if you have a connection, add /sbin/modprobe <driver name> to your /etc/rc.d/rc.modules file for it to load automatically at boot.
oh yeah, if your kernel does not support your hardware drivers, you'll have to recompile it. so let's hope it does.