If you're only going to pick one author from whom to study Kabbalah, then Rabbi Aryeh Kaplan is my recommendation. I hold him in such high regard that one of my children has Aryeh (meaning lion) in his name.
Here is an interview with the late Rabbi Aryeh Kaplan to gives an introduction to Kabbalah.
If you are unfamiliar with the terms Torah and Talmud, they refer to the Jewish written law and oral law respectively.
This blog, Trainee Golem Builder, was set-up to track my progress towards understanding Kabbalah from a theoretical and meditative perspective well enough to know how to build a golem.