I made an instance previewer, so you can see the local/federated feeds of an instance without signing up: http://www.unmung.com/mastoview?url=xoxo.zone&view=federated
Another detailed .gif on how to get verified.
The @Support account is official, a couple dedicated people helping users with questions (I do not personally post from it though)
So, heise.de wrote an article about Mastodon.
German language, obviously.
Server run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!