hello and welcome.
It is relativly simple.
I hope you have baught the correct grapphics card type, there are 2 types of graphics card, pcie & agp.
If you have the correct one, it is as simple as opening your case up and slotting it in.
here is a guide for agp
http://reviews.cnet.com/4520-3118_7-5023982-1.html
for pcie
http://www.youtube.com/watch?v=femSBniU ... ed&search=
so whichever your pc has, follow those
if you need help take a picture and show me. Once the card is installed, you connect your monitor to the card, and then you can download and install latest drivers.
if you have baught an agp card, and your pc is pcie you cannot install it, and vice versa.