I could not get the classes to show up in the table view.
In the text it says, "Control-click on the table view to bring up its Connection panel. Make RanchForecastAppDelegate the data source for the table view."
I did that.
I also needed (under Referencing Outlets) to connect tableView to RanchForecastAppDelegate.
Now the classes appear in the table view.
This book is really good. I hope it will be updated.