We post regular updates to our Instagram, where you can get sneak peeks of map progress, as well as nice screenshots and renders of older maps. We use twitter less often, but still for announcements of update letters, etc. Our other major platforms are YouTube and Planet Minecraft.
We post cinematics of all new maps on YouTube, and there you can find a wealth of videos by Lockrules regarding the server and other topics in Minecraft. Planet Minecraft is the place where the public can find all our maps, although the maps themselves are hosted by us.
Finally, we use Discord as our major means of communication within the build team, and its vital you join if you want to become involved in the server.