Are you using a wireless keyboard/mouse? Those won't work in a Live CD environment. You'll need to use a wired keyboard and mouse instead.
As for your second question: There is no BIOS to get into. Then again, you don't need to go in there just to load a Live CD. Insert it, reboot your Mac, hold down the Option key after the startup chime sounds - this will summon the boot manager. Select the CD. Presto - your Mac will boot from the disc.