Common symbols of hinduism are the swastika, trishula, yantra, talik, pratik, lotus (a flower that is considered a gift of god, linga, bindi (dot worn on women's forehead) and Om (essence of the entire universe).
The OM and Swastika are symbols I've usually seen to a lot in Hindu culture. The "OM" is a sacred sound of all mantras and of the universe. The swastika is a symbol of good luck, fortune and well-being and not to be confused by other usage in history.
The lamp, lotus, conch,and the color saffron are major symbols for Hindi believers. The lamp is a powerful image for light or truth. The beautiful lotus flower has it roots in the mud, but is untouched. Love is indicated by the conch. Saffron denotes the fire of the Supreme Being.