Normally, you need only to install the drivers that come with the motherboard driver cd.
They may not be the absolute latest. If you have some issue, then go and get the latest drivers from ASUS.
Do not simply install "all" or you will get many apps that you may not want. Install drivers only.
Updating the BIOS always has the possibility of bricking your motherboard. Do so only to fix a bothersome problem.