Don't berate yourself too much. Everyone learns the same way. By instruction and experience.
If your graphics now is on-board, just install the new card (physically), boot to Windows. If you have Win7, it may even load a basic driver for the that card. If not, download and install the driver for it. (You can use the one on DVD that came with the card, but it is probably a bit out-dated). Follow the direcrions and you will be good to go. After all is up and running, do yourself a favor and run CCleaner to clean up the computer of resource wasting crap and registry errors.http://www.piriform.com/CCLEANER