This video talks about the basic timing of CW / Morse code elements (dits and dahs), and how to send them using a few device - such as a traditional straight key, as well as using a dual-lever paddle with an electronic keyer. Iambic keying with a paddles is also described and demonstrated.
Notes from the video: http://www.qsl.net/w2aew/youtube/Morse_Code_Timing.pdf