Which video card should I get?

The fan on my video card stopped working and so the video card overheated and now I need a new one. I have a Pentium 4 CPU 3.2 GHz. I used to have a Radeon 9800 xt but I'd like to replace it with something better but I don't know what my computer can handle. Don't know how to find out if I have a AGP or PCI slot and I also don't know how to find how much power my power supply has.|||well a Radeon 9800XT is an AGP 8X card, so my guess is you'll be able to upgrade to an AGP video card......best bang for the buck in my view, its the Radeon HD3850 AGP.....