Replacing dimmers and lights from spur?

My bedside lights and dimmer switches were attached to a fitted wardrobe which I removed; on connecting the new lights and dimmers, I noted that the power comes from a fused spur which is located alongside the plug.

The wiring at the switch contains two cables, each containing live, neutral and earth. The wiring at the light is a single cable, containing the above.

I'm assuming that one of the cables at the switch is the power coming up from the spur, and the other goes to the light.

My questions are:

1. Where do I connect the wires into the new dimmer switch (it has L1, L2 and the squiggly line)?
2. Do I need to both of the dimmers and lights in order for this to work?

Thanks in advance.