Is there an updated tutorial anywhere that reflects the current software and included templates/databases?
Many steps in the existing tutorial are missing/don't work, and the sudden, inexplicable leap from Part I (wherein you are to learn how to create a Customer DB to go with an Invoice DB) to Part III (wherein you are suddenly dealing with Persons, Books, and Readings) is absolutely jarring, and makes little sense. Commands in Part III don't exist, and steps are missing, to boot.
Why on earth doesn't the tutorial just continue with Customers and Invoices? Suddenly you have to stop and build new tables and populate them? Crazy.
Images also appear very outdated, and don't reflect the current Mac version at all.
I understand your frustration. There are a few organizations that run blogs and such.. Check out the following:
ninoxus.com is later this week changed to nioxus.com and is a very well reference to find manuals and videos. Check also the chanel ninox learning on youtube hosted by nioxus.com fir videolessons.