There's many measurements a multimeter can perform. The checks mentioned in your thread have been all Voltage measurements.i do have the multimeter now however to be honest i have no idea how to use it to tell me anything.
Voltage Measurements
A typical analogy for a Voltmeter is a relative pressure gauge. Pressure indicated is the difference between the circuit being tapped into and atmospheric pressure.
A Voltmeter is applied between two reference points same as the pressure gauge above. For instance the battery + terminal and Frame ground. For a lot of the wiring voltage tests, once you have gotten past the Battery + Terminal/Frame ground successful test, you can leave the black meter lead on frame ground, and move the red probe to the downstream areas.
-- Initial Setup --
Set meter to the 20 DC Volts scale. Make sure the meter leads are connected to the correct jacks in the meter.
-- Measurements --
We are checking for connectivity. The actual voltage reading is not too important, nominally should be about 12.6v or higher.
1) Battery + terminal (Red DMM Lead), Frame Ground (Black DMM Lead)--> Expected reading +12v
2) Leave Black DMM Lead connected to Frame, Check the Fuse at both sides with the DMM Red Lead --> Expected reading +12v
3) Measure Ignition switch Red wire with the DMM Red Lead --> Expected reading +12v
4) Switch the ignition switch ON, Probe Ignition switch black wire with DMM Red Lead --> Expected Reading +12v.