Your next step should be to carefully read the job description of the position for which you wish to apply. (topresume.com)
Find out who will be reading your cover letter, and go through the job description of the position for which you are applying to see what is required from you. (coverlettersandresume.com)
Depending upon available space, you may only want to give one or two lines in description of these positions, if any at all. (theresumeclinic.com)