Excellent general sources
Stanford Encyclopedia of Philosophy (SEP)
Internet Encyclopedia of Philosophy (IEP)
This worldwide bestseller follows 14-year old girl Sophie on a journey along the main figures of Western philosophy. An excellent read for anyone over 12 years old.
Sophie’s World– Jostein Gaarder
Contains comprehensive articles on all famous western philosophers until 1945. Bertrand Russell was a great thinker himself, making tremendous contributions to philosophy of science, logic and mathematics.
A History of Western Philosophy - Bertrand Russell
Comprehensive, complete, dealing also with the greatest minds of non-western philosophy, who in fact appear to address the very same questions sometimes ascribed to western thinking only.
The History of Philosophy – Anthony Grayling
David Hume wrote one of the most inspiring and groundbreaking philosophical texts of western philosophy, dismissing all metaphysical twaddle in favour of seeing the world simply as we experience it.