There are various things configurable in Jenkins, like the location of JENKINS_HOME, some JVM options, features controlled by system properties etc.
Installers place startup scripts on the file system in various places.
There are also some outputs from Jenkins, such as log files.
Depending on the installer used (e.g. none, Windows, OS X, Red Hat, Debian etc.), these config, system, and log files will be stored in different places.
Ideally, there should be a page for each type of installer, in a standardised page format, which specifies where to find the log files, what they are called, how to set the various configuration options, how to start/stop/restart Jenkins etc.