Lighting circuits as found in domestic properties in the UK.
Trial and error?
Lighting Circuits Overview
Types of Lighting Switches
Lighting Circuit Switch Arrangements
Lighting Ceiling Rose Wiring
Looped Ceiling Rose
Older colour codes for ceiling rose
Lighting Circuits using junction boxes
One Way Switched Lighting Circuits
Two way switched lighting circuits
3 way switched lighting circuits
Loop at Switch Lighting Circuits
Lighting Circuit diagrams for 1,2 and 3 way switching
Series and Parallel circuits
Do not start work on the lighting circuit in your home at 4pm. Trying to install light fittings in the dark is not safe or easy. Further, it is usually the case that removing wires from one ceiling rose will result in most of the other light fittings in your home not working.
Lighting circuits are not usually complex or difficult to understand. However the fact that there is a switch included does seem to cause issues, particularly when someone has purchased a fancy new light fitting from B&Q, pulled down the old ceiling rose, and then finds 9 wires in the ceiling and only 3 connections in the new fitting.
Connecting the wires in various combinations and hoping one of them is correct is doomed to failure. Always make a note of the wiring arrangement before removing the old ceiling rose. Digital photos are a quick and easy method of recording the old connections (use the camera in a mobile phone).
All of the usual safety rules apply, but as lights are often ceiling mounted, use a proper stepladder. Do not be tempted to use a chair or any other piece of furniture.