Upgrading your bios can be done in different ways, depending upon you Mobo manufacturer. Sometimes there are updates to fix a known re-occuring problem with that board or just to allow new componets to be installed. I would check out the revision information for the Bios upgrade that you are looking to preform. Also, check your motherboards manufacturers website for 'How to perform a Bios upgrade'. Usually you flash your bios after downloading the update. Sometimes this can be done from windows sometimes you have to do it from a boot drive.
if it aint broke don't fix it. if you are not installing something that would require a bios update then it is best that you just leave it alone. the only advantages would be better compatibility with newer parts.
BIOS updates can make your system more stable etc. It isn't too much a hassle to do it, however, I would look at the "changelog" of what the BIOS update fixes (or adds) before deciding if you want to do it or not. Some manufactured computers, such as Dell, are updated via a software program you simply run and it automatically updates the BIOS for you on the next bootup. Most require placing the BIOS update on a floppy or flash drive and booting to the appropriate media. The update takes over from there in most cases.
a disadvantage of a bios update is if you do it wrong then good chance you'll be buying yourself a new motherboard unless still under warranty.
