From http://askubuntu.com/questions/57381/how-to-stop-mysql-from-running-at-boot-time

services.md

As Apache still uses the traditional SysV init scripts you can use

sudo update-rc.d -f apache2 remove

to remove the links from /etc/rcX.d or, alternatively use

sudo update-rc.d apache2 disable

which "disables" the script by changing it from a start script to a stop script. This is reversible by

sudo update-rc.d apache2 enable