The definitive guide for R/T in the UK is CAP 413:
http://www.caa.co.uk/docs/33/CAP413.PDF
Couple of points though:
- When talking to "Approach" you're talking to the person who's job it is to line up the aircraft for landing, but not the person who gives joining instructions/landing clearances. That last bit is typically done by "Tower".
For some VFR arrivals you need to talk to Approach to obtain a crossing clearance, because that's the airspace you're crossing (CTA or TMA). Eventually you end up in the CTR, where you're told to switch to Tower, who will give you circuit instructions and eventually a landing clearance.
On the other hand, if you approach underneath this airspace you typically don't talk to Approach, but go to the Tower direct.
- If you're flying on a flightplan to a controlled airfield, or if you're returning from a local flight or to your home base, they typically have/know your details already so in actual practice you don't pass the full message but just the important points. This works just fine at my local field:
"Rotterdam Tower, PH-ABC overhead Dordrecht 1500 feet with information Z for the Romeo arrival."
The Romeo arrival of course is a standard and published VFR arrival route.
On your exam, your job is to regurgitate whatever is in CAP413. After your exam you're very welcome in the real world.