My advice: do not dive right into philosophy. I have seen far too many individuals burn themselves out on philosophy by jumping right into deep end of the pool, attempting to read Descartes, Kant, Locke, Berkeley, Nietzsche, Plato, pre-Socratics, and co. Instead of picking up the first copy of Being and Nothingness by Sartre, try some of the commentary books, as some of the 'second-hand' philosophy can have a lot to say, too. I would even think it safe to say that Joseph Campbell, Paul Woodruff, Leonard Shlain, and James Carse have taught me things about philosophy that I would have never learned myself from its original sources.
Shorter philosophical essays can create some ease on your brain, too - that way, your cerebral cortex does not have to fully envelope the hundreds of pages of The Republic. A few notable essayists: Ralph Waldo Emerson, Henry David Thoreau, Michel de Montaigne, and David Hume had some shorter works, as well.
Lastly, fiction can contain immense quantities of philosophy. Fyodor Dostoevsky instructs a lot on existentialism, Albert Camus and Franz Kafka on absurdism and ethics, Herman Melville on virtually everything, and Leo Tolstoy on spirituality.
Good luck!