Do I have to physically open my case and look at the slots? If so, what am I looking for?
You do realize that opening the case will be required to install your new video card? Right?
Sorry couldn't resist! LOL
PCI-E slot is located apprx. 1 1/2" from the M/B edge and slot is apprx. 4" long including the locking tabs
AGP slot is located apprx. 2 3/8" from the M/B edge and slot is apprx. 3" long
PCI slot is also 1 1/2" in from the M/B edge but the length is 3 1/4"
Another thing you may need to take into consideration besides M/B slots, is will your present Power Supply handle what you want to upgrade to?
So what are your full specs?
And are we talking Dell, Gateway, HP ??? Etc. if it is a brand name PC what brand and model #.
You may as well start self educating yourself on these things unless you'll be getting someone else to do it for you.
However there are a few here that will help you if you plan on doing it yourself.