I too found the chains to be tricky the first time, and the center cog, a PIA. But here is what I ended up doing.
Fold the chain in half, use a sharpie to mark both sides of that center link.
Put the chain in, and press the marked link on the "square" cog. The square cog is the center one on the sprocket. The rest of the links should easily lay down.
And yes there are a few "needles"
