The update-rc. d utility has already been mentioned, and is one of the primary command line interfaces for managing init scripts. However, there are several other utilities that are essentially a frontend for update -rc . d that make the administrator's job a little easier. The primary ones are bum and sysv-rc-conf.
The Boot Up Manager, or bum, is a graphical application for managing init scripts. It requires a window manager to run, and provides a nice interface showing what services are running and what scripts are enabled. In advanced mode, it will also allow you to adjust individual run levels and run order.
As mentioned for the update -rc . d start and stop commands, adjusting script ordering is not recommended.
There is also a utility called sys-rc-conf. It uses the curses library to provide a full-screen text interface. Inits default mode, it will not modify script order, although special options on the command line will allow this if you really need this functionality.
Both utilities are pretty much self-explanatory. Check the services you want, uncheck those you don't, and you can set or unset check marks for different run levels on the same script.
Frequently, you will need to execute a SysV script manually, either to check the status, or to restart a service that requires it. Although the script in /etc/init. It may be executed manually, the recommended.
The method is to use the invoke-rc. d command, which ensures that system policy and run level constraints are satisfied.
If you need dedicated infrastructure for Debian-based applications, consider a United Kingdom Dedicated Server for greater control over SysV scripts, service startup configurations, system processes, and server resources.