I'm guessing your not a Driver Nazi? TBH if your not having any issues with your current BIOS and theres nothing apparent that you'll gain from updating it, I'd leave well alone.
If you really want to however. Its usually a case of putting the various files onto a floppy, booting from it and "flashing". Its a very good idea to make a backup of your current BIOS beforehand (someone else will have to fill in that one). However I think allot of the newer motherboards now let ya do it from within Windows. AFAIK
its a one click job with my Asus A8N board and the supplied software, allthough I havent seen the need to bother yet.