For first call to any type of ATSU you should state what you want, so "Manchester Approach, G-BGZE, join" or "Farnbrough Radar, G-XXXX, basic service"
Whether it's Approach, Information, Radio etc depends on the type of service provided, you will have worked that out in your pre-flight planning. Arriving at a larger airfield you would normally talk to Approach initially then by the time they transfer you to Tower they will often have passed your details - in which case you would be told "Golf Zulu Echo call Tower [frequency] callsign only" If there's an ATIS, that will tell you what additional information to give in your detailed 2nd call, for example Lydd might want you to say "with information Charlie, QNH 1018"
Then when asked to 'pass your message' give the full details as you have written.
Don't abbrevate your callsign until the ground station has abbrevated it first - you don't know there isn't another aircraft on frequency with a similar one.
Edit - further guidance here
http://www.caa.co.uk/docs/33/Aviatio...917_LOCKED.pdf