PCs can have many different video card manufacturers and models, just as cars can have many different types of makes and models.There are primarily two large video card manufacturers, ATI and nVidia along with Intel following closely.
For the most part, ATI, nVidia and Intel drivers are very simple and fast to install.
Please read General Binary Driver Guide for installing ATI , NVIDIA drivers , info about Xorg and more :
Webcam - Guides on installing and managing Webcams.
Firewire - Hardware, drivers and software for getting ieee1394 (Firewire) to work
Asus_P7131_Dual - Help on installing an Asus P7131 dual DVB card.
DViCO Dual Digital 4 (and probably other DViCO cards) - How to get the DViCO Dual Digital 4 DVB Card (and most likely other DViCO cards like the NANO, FusionHDTV DVB-T Pro and Dual Express) working.
If you have a question that is unanswered, please visit the Ubuntu Forums and feel free ask questions! Try some of the following threads:
Beginner Talk - Where you can ask any kind of question.
Hardware & Laptops - Where you can see if your video card/hardware is supported. On this thread, you can ask questions about installations of video cards/hardware that are not mentioned here. Please refer to this section while in discussion on the forum so that this page may be updated if needed.
Graphics card not working correctly? Please follow the procedure in GraphicsTroubleshootingProcedure in order to get help from the Ubuntu community.