Is there anywhere that gives a tutorial on the steps required to make a some simple configuration settings to be added to the configuration menu? I believe it is a case of writing an SQL patch to set it up but have no clue how to format it?

What I am after is a simple on/off setting to be either added to an existing configuration menu or to be located in a new custom configuration menu.

If there are any guides or if anyone can show me how to do this id be grateful.

Cheers
Phil