Although I have not studied the Kabbalah at length, I have wanted to read the basics for quite some time. I was fortunate to find a text which was reported to be a rather accurate translation. This book was a good place to start - it offered an overview and explanation of basic beliefs.
Much of the text I read contains very subtle meanings, suitable for meditation. If you do not ponder the text of the Kabbalah in solitude and quiet you will not get much out of it. Like a delectible morsel, the Kabbalah is to be savored - one thought at a time.
After reading, the most important concept I brought from the study was the eternal, infinite state of God. Traditional Judaism, like Kabbalists, are careful not to define God. They figure doing so sets even a minor limitation on God, Who is Eternal and Infinite in all ways. This also is the reason his name is not to be spoken. By imposing mental images or concepts on what or who we think God is, creates a form of idolatry - spiritual idolatry.