Firstly there are no CAA approved PPL schools. If you wish to give instruction as a sole instructor you must Register with the CAA see AIC 67/1999
http://www.ais.org.uk/Uk_aip/pdf/aic/4W355.pdf
Once registered you may give instruction from a licenced airfield. If the aircraft is solely owned by the person you are training, you may be payed as well, but if the aircraft is group owned then you cannot be paid on a private cat aircraft.
[This message has been edited by Noggin (edited 11 June 2001).]