I guess you already figured out which is the AGP slot, I just have a few things to add....
1. ALWAYS ground yourself (touch the metal part of the case) while working inside the computer.
2. allow at LEAST 1 hour of cool off time before opening the case.
3. With Intel chipset based MOBOs you don't need to disable anything in the BIOS (which you get to by pressing F2) Windows will detect the AGP slot and use it.
4. If it is an intel chipset, then you need to configure how much memory your card has in the BIOS, b/c it just says 64MB
5. Download the latest drivers for your card, always a good idea.
6. make sure that you properly seat the card, I.E. it snaps into place, or else it might shortcircut.
7. Don't tighten the screw too much (i mean over-doing it) or you might crack something.
8. The first time you use it, make sure your case isn't overheating... Vidcards add a lot of heat.
Chris