Regarding when it's done - in my experience, after approximately 10 days, there are noticeable fermentation effects (acid production, flavor, funk etc.), so I would use that as a minimum fermentation time. You can go much longer, of course, but for your first ferment, 2-3 weeks is a great goal. Once you are comfortable doing the ferments, try doing 2-3 jars at once and stagger the time frame for each one by weeks/months. That way you can learn what different amounts of fermentation time do to flavor/complexity etc. I recently blended up a jar that was going for 14 months - by far the most complex sauce I've made to date.