Karma?

This was the clearest explanation of Karma I had read, It is from the first Buddhist publication I had purchased, the book is The Tibetan Book of Living and Dying This book changed my thinking forever.

What Does Karma Mean?
In simple terms, what does karma mean? It means that whatever we do, with our body, speech, or mind, will have a corresponding result. Each action, even the smallest, is pregnant with its consequences. It is said by the masters that even a little poison can cause death, and even a little seed can become a huge tree. And as Buddha said: "Do not overlook negative actions merely because they are small; however small a spark may be, it can burn down a haystack as big as a mountain." Similarly he said: "Do not overlook tiny good actions, thinking they are of no benefit; even tiny drops of water in the end will fill a huge vessel." Karma does not decay like external things, or ever become inoperative. It cannot be destroyed "by time, fire, or water." Its power will never disappear, until it is ripened. - Sogyal Rinpoche,
The Tibetan Book of Living and Dying and included in Everyday Mind, a Tricycle book edited by Jean Smith