[Articles]
You may find a barely satisfying collection of manuals from English version official website.
Actually, since the developers are Chinese, you may find richer recourses from Chinese version official website but unfortunately you may read them via the help of Google translator extension.
[Videos]
Besides the rare and superficial English teaching videos you may have found on YouTube, here are a bunch of teaching videos from Marginnote Chinese users and you can select the ones with highest clicks. Although you cannot understand the speaking language, I hope the lively demo can still help you.