When you were learning to write your name, you were probably taught to write the letters in a certain order and direction. That's because it is more efficient to write western languages from left to right. For similar reasons, the strokes for each Chinese character are to be drawn in a certain defined order.
At first you may need help from a teacher, book, or other learning aid to determine the stroke order for characters you encounter. The more characters you become familiar with, however, the easier it becomes to see which principle applies to a given character.
In short, learning these following seven principles of stroke order will ultimately save you from having to memorize rules character by character.