What would I need to make my lens reversed compatible?

I have the Nikon D5000 and the standard 18-55mm Lens that came with it.

What do I need to make it reverse compatible for macro shooting?

You will need a prime lens, like the 50mm f/1.8 for example.

Here is my reverse macro set-up with a 70-300mm and a 50mm f/1.4 on it:

The problem with the 18-55mm, is that even @55mm, you will get a circular "hole" and/or extreme vignetting.

Then, you will need a reverse macro ring [like a 52-62, or 52-68mm] to hold the two lenses together.