The best resumes are always written in reverse chronological order. That is, your most recent position is at the top followed by your previous postion, and so on. Althougth it seems counter intuitive, that the story of your life should be told from the beginning to the most recent. Your last or present position is usually the most relevant and will have a greater baring on the next job you aspire to. This also makes the resume timeline very clear and easy to read for a hiring manager.