In reply to bigrob:
don't need massive geological knowledge, agree Mikes book is a summary but that is
the level, remmeber you are trying to inspire/educate clients not teach a geology course.
re talk - what are you interested in ? I did mine on PTSD and climbers very left-field for
most people ! Others in my group did Comedy in mountaineering literature, One climb
on Ben Nevis, Rescue helicopters privatisation (i think!), and some plant stuff which
was good as well. they were all good (must have been another one !) I nearly did
invasive species in snowdonia (like rhoddys etc) ....
PbyaB suggestion is sound as it will make you focus on something that you may/will
need - like maybe tryfans geology. But whatever floats your boat.