Which are the best online Amazon seller training courses?

There are a number of prominent Amazon seller training courses available online: There is Amazon's own seller training,  which offers an abundance of training tools and videos, including a dedicated FBA YouTube channel.  Outside of Amazon, you have Justonedime.com, who offer you hours of live coaching and one-on-one strategy meetings with Amazon coaches, in addition to access to many valuable tools, hacks and strategies; at Udemy.com you can search for and find a long list of Amazon seller training courses. There are also podcasts, such as Amazing Seller Podcast, AMPM Podcast, Private Label Podcast, and of Facebook - the Amazing Seller Facebook Group.  As with other online Amazon courses, one needs to be careful and separate the weed from the chaff. For those starting out selling on Amazon, it's nearly always recommended to start out with the "official" resources.