>>7
Any one will do, really. All you need from the intro books are the general "tools" and reasonings of philsophy which are:
Logic
Epistemology
Ethics
Metaphysics
Aesthetics
and how they apply to:
Political Philosophy
Philsophy of Science
Analytic Philosophy
Psychology
Philosophy of History
Empiricism
Theism
Idealism
Pragmatism
and so on...
"Philosophy for Beginners" by Osborne(?) is a kind of a comic book for tourists of the subject focusing on major thinkers and their influence on the Western canon. The summaries are well written even if they are leaving out some important-but-esoteric details. If there's someone mentioned who sounds interesting, look up what their primary works are and maybe their critics.
The best thing I can advise is don't get too caught up in the history and biographies - look for interesting ideas and have fun testing them.