Minecraft Official Website – the home of Minecraft

Notch’s Tumblr – important updates and some other stuff by Notch.

Docm77’s Minecraft World – Docm77’s website, loads of great content about Minecraft

Minecraftaddict on Reddit – MinecraftAddict’ reddit thread. Lots of great minecraft engineering

Zhulslab on Reddit – Zhulslab’s reddit thread, another great source of Minecraft inventions.

PureBDcraft Online – The home of PureBDcraft. One of the most amazing texture packs out there!

Crafting an Empire – McFly’s blog chronicling his progression on building an empire in Minecraft.

Dead Workers Party – the Dead Workers Party, creators of Control Point, a TF2 related podcast, and The Shaft, a Minecraft related podcast.