I recently got involved with doing some sewing work myself and have really enjoyed it. I've helped with making a mainsail for a Soverel 30, a spinnaker for a J29, and an assemblage of seat cushions and whatnot. In general, it's work that anybody can do, but there are definitely some tricks to it that are not obvious.
What I found to be really helpful in getting started learning about doing sewing work was to take a course at the local technical college. It cost me about $30, but having an experienced upholsterer and sailor teaching the class was invaluable. Also, the access to heavy-duty sewing machines was very nice for working on difficult portions of the project, such as the reinforcement patches near the head, tack, clew, and reef points.
Finally, to keep this post on topic, the instructor was a great resource for sewing machine advice. She was able to explain what manufacturers had repair shops in the area, what features to look for in sewing machines, etc.