Software for cutting thin ply, peferably free

Hello all, I recently got access to a small router from china and have been working on cutting out some parts from 1/8" ply. So far I have written the Gcode by hand and it seems to be working ok. It has a 1/8" collet and I use zip bits to cut because they are cheap. At about $1 each I can throw them away if they cut one project.

I need to cut more complicated shapes and have modelled them in lightwave. I downloaded a bunch of programs from cnc4free site but am only confusing myself with it all.

How best to lay out the shapes to cut given its really a 2d job ?

suggestions appreciated.