Michael Martin is a trader and instructor. His show deals with the emotional and psychological aspects of trading and managing risk. His book "The Inner Voice of Trading" and features interviews with Michael Marcus, Bill Dunn, and Ed Seykota - who also wrote the Foreword. Get the audio book free at MartinKronicle.com.
If you know what your target RoR needs to be, you can determine the number of trades you need to make knowing your winning % and ratio of average winners to average losers.