Ashton,

Welcome! I would recommend the Zhuangzi/Chuang Tzu as one of the most pivotal texts, as well as Liu An's Huainanzi. The Hua Hu Ching is a book of unknown authorship which may or may not tickle your fancy. Taoism isn't a single "ism", it is a school of thought, but that which is closest to the origin of that school of thought are the writings of Laozi (Tao Te Ching) and Zhuangzi (The Zhuangzi). If you want a commentary to elucidate the sometimes daunting I Ching, Wilhelm's commentaries are EXTREMELY enlightening, as I have mentioned in another thread.

As you study, keep in mind that none of these authors have authority. My stance towards the readings is usually simply contemplative, neither agreeing nor disagreeing, just noting where these things may be true in life, but if your experience is different than that of an old master, do not hesitate to note this and observe further (but don't try too hard to refute. The tao isn't found in meaningless concept shuffling!). Happy journeying!

-TaoSandwich