Cartography
This server has an overworld map at mc.rts.pub/map, powered by Little a Map. It updates once per minute but doesn't auto-refresh, Keep your F5 finger ready.
How It Works
The map reveals itself as players explore. Create in-game maps to add tiles, and place banners to add markers. Maps in your inventory won't render, so stash them in a chest.
For details, see the Minecraft Wiki or check out this example map. Still confused? Ask the server admin.