I donno if i m posting this problem in a right section or not.. but this is a big prblm for me!!.. so if i posted in wrong section then plz lemme knw where to ask for help for this one

I a complete newbie to linux & when i read abt it i found the ubuntu version the most friendly of it.. so i decided to install it.. but after installation i hve a major prblm
Ma graphics r not displayin properly.. i mean i can change the screen resolution & the screen looks good without any faults.. but the whole screen size has reduced.i hve a dual boot system with windows xp. Windows runs smoothly but ubuntu doesnt as screen size is not coming proper.
i hve Asus-k8v-mx mobo.i read abt its graphics drivers for linux & tried to install it. But i think i screwed up somewhere coz dere was no change .So if anyone can plz provide any help for this then i"ll be really grateful coz i really wanna be a linux user but without proper graphics it"ll be hard for me.
So plz reply in an easy step guide on how to install ma drivers properly if ya can
Thanx !!