http://www.amazon.com/Hacking-Electronics-Illustrated-Makers-Hobbyists/dp/0071802363/ref=pd_sim_b_3
That is the U.S. Amazon, get the UK equivalent.
I have met Simon, the author, a few times, top chap, he is on this forum from time to time.He knows his stuff and has a way of putting it over for beginners.