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 :
If your graphics card is not working correctly, follow the procedure in GraphicsTroubleshootingProcedure in order to get help from the Ubuntu community.
Webcam - Guides on installing and managing Webcams.
Firewire - Hardware, drivers and software for getting ieee1394 (Firewire) to work