Thanks for the advice. Especially Kay. (The techie part is just a place to upload photos, so you can put them on forums like this). As preparation (just to downer really), I'm practising my map and compass skills first, including following paths from the map when faced with two or three in the same spot. Then I'm going to read "The Complete Caving Manual" by Sparrow (http://www.inglesport.com/shop/catalog.php?page=2&category=Caving%20Books) . According to this site Greak Douk is a I out of V , and is suitable for children children tend be a bit more compulsive than adults so I should be OK. http://ukcaving.com/wiki/index.php/The_Three_Peaks
You could say I will be learning on the job, but you always do on your first caving/fishing/scuba trip don't you? I will be aware of the risks from the book.
To the inviter in the post above this : Thanks, but the trip will probably happen before I've read my book and bought my suits.
If you ask me this is a lot of preparation. Considering you can go on the roads after a just a weekend motorcycling, if you hold a full license.
I will inform the pub landlord where I am and when I expect to return, so he can come and get me with his yellow chopper.