Need help: How to replace NIC card with another brand

[gary@garynielson.com (Gary)]

I need to replace my NIC card and have an Intel NIC card as a
replacement. The system is already built and configured for the old
card. Do I need to add the module to the kernel? I have never done
that after building the system, so how do I go about it? How do I
configure the NIC for 10 meg speed and half duplex?
System is woody, kernel 2.4.