Summarize this article:

Since BIOS menus don't support mouse input, you'll need to use the arrow keys and other computer-specific keys to navigate the BIOS. You can usually find a list of controls in the bottom-right corner of the BIOS homepage. When adjusting settings in your BIOS, be sure that you certain what the settings will affect.  Changing settings incorrectly can lead to system or hardware failure. If you don't know what you want to change coming into the BIOS, you probably shouldn't change anything. If you want to change what device to boot from, enter the Boot menu. From here, you can designate which device the computer will attempt to boot from first. This is useful for booting from a disc or flash drive to install or repair an operating system. You'll typically use the arrow keys to go over to the Boot tab to start this process. You can create a password that will lock the computer from booting unless the correct password is entered. Your BIOS’s clock will dictate your Windows clock. If you replace your computer's battery, your BIOS clock will most likely be reset. These options are for advanced users only. In this menu, you can overclock your CPU, potentially allowing for higher performance. This should be performed only if you are comfortable with your computer’s hardware. When you are finished adjusting your settings, you will need to save and exit by using your BIOS' "Save and Exit" key in order for your changes to take effect. When you save and restart, your computer will reboot with the new settings. Check the BIOS key legend to see which key is the "Save and Exit" key.

Summary:
Familiarize yourself with the BIOS controls. Change your settings carefully. Change the boot order. Create a BIOS password. Change your date and time. Change fan speeds and system voltages. Save and exit.