As the question is clear from the title, how do I change Linux services startup/boot order?
You can change the order by renaming the symlinks under /etc/rcX.d/ where x will be your run level.
You'll see a bunch of files starting with Sxx or Kxx. S links are traced during startup while the K ones are parsed for shutdown. The xx here represents the order.
But this order is set for a reason, so be careful while changing them.for example. ntpd should start only after the networking subsystem is initialized.
You want to read a little about your runlevels and rc.d directories. Inside the rc.d directories you can find the S and K links, like S20apache K10apache, that is basically what orders startup/shutdown of scripts.
There are some changes being made on this architecture but most of the linuxes are still using it.