Dear friends!
I am a new one of device driver field. I want to know abt,
is the linux2.6 with inbuilt kernel program for such hardwares USB and VGA? or We need to write the own kernel program for THAT hardawres? wat abt Keyboard and Mouse?
Waiting for u'r kind info....

If I understand you correctly, you graphics card will run fine in vga/vesa mode without anything extra needed, also most mice and keyboards including usb keyboards and mice will work fine without any extra software required. If you require further functionality, you may need a 3rd party driver for your graphics card (if it is nvidia or radeon etc.) to get 3d accelerated games working, or the synaptics driver to get full functionality for a synaptics touchpad, or bluez libs to get bluetooth devices working correctly (although I haven't tried any bluetooth devices on my system).

Furthermore... when you use many USB human-input devices, the piece of software that's actually using it (mostly) is XWindows or XOrg. The kernel has very little to do with these devices.