Prepare job summaries, if relevant. You can use the job description template you use for each position that you advertise by filling in the template with the information that is relevant to that position. However, if you do (or expect to do) a lot of hiring of a particular position, you might make a special template that includes a summary of that job. This will save you some time.
The process of developing job descriptions often sheds light on the nature of a job as well as suggests that there are alternative methods of performing essential job tasks. Job analysis may help encourage management and staff to work together in identifying and streamlining the essential and marginal job functions.