We now are including formal training in the use of the GPS functionality into our navigation syallabus. This will be done in a session after the basic nav.training but before the QXC (qualifying cross country) and will comprise ground training and use in flight.
Folders with relevant information are to be found in briefing room 1. GPS 430 simulators have been installed on each of the briefing room computers (as this previous post refers). Although appreciating the more complex facilities of the GNS430 is the ultimate goal, at the pre PPL Skills Test stage interpretation of the map, use of the Direct To button (without infringing!) and ability to locate nearby airfields will be emphasized.
If you want to get ahead of the game (or are a qualified PPL but ignorant) then this AOPA website will set you up!