Submitted by Federico Voges
This is not really a step by step, just a small tip. I'm submitting it because while googling for it, I've found that it's really a FAQ. Just put this line:
/usr/sbin/setterm -blank 0 -powersave off -powerdown 0 >& /dev/null
in your /etc/init.d/boot.local, /etc/rc.d/init.d/rc.local, /etc/init.d/rc.local or whatever your distro uses.
/usr/sbin/setterm -blank 0 should be ok, but the other options won't hurt ;). And don't forget to RTFM (man setterm)!