Thomas Nagel, What does it all mean? (Oxford, 1989)
Nigel Warburton, Philosophy: The Basics
Nigel Warburton, A Little History of Philosophy
Stephen Law, The Philosophy Gym
Simon Blackburn, Think: A Compelling Introduction to Philosophy (Oxford: Oxford University Press, 1999)
The following is a must-have if you are serious about Philosophy, as it provides you with primary source texts from many major philosophers. Dipping into this book is very much encouraged.
Nigel Warburton (ed.) Philosophy: Basic Readings.
More advanced reading
Jonathan Rée, Witcraft: a History of Philosophy in English