New to it all, where to start?

Hi all.
As time is closing (fingers crossed) to the peachy being ready for shipping I thought I'd ask a few questions too get ready.
I'm new to the whole world of 3D printing, I've read a lot but I'm still not sure where to start.
A few things I'm unsure about is:
Which CAD program should I be learning to use for the peachy? I read a little (read very little) that the creators have developed a plugin called blender?

Do you have some tutorials suggestions I should read regarding good designs, IE not too thin walls, create supports and leave draining holes etc?

Thanks in advance for any help.
Jon.

Blender is a 3D modeling program you can create plugins for Blender.

The Blender plugin is suppose to take the 3D model and export it into a .wav formated file from the gcode and encode the audio with the data so the peachy printer can move the mirrors in the correct positions.

There are many 3D programs you can use to make models. Just to name a few.

Blender
OpenScad
Google Sketch up
Maya

To clarify what 3D Monkey is saying,

They were originally going to make their software work directly with Blender, but they found it was much easier to make a gcode converter instead, since gcode can be made from any slicer and those can accept stl files made with any modeler.
Basically, you'll need to slice your model in an existing slicer software and then run the gcode through their converter.

I recommend FreeCAD or SketchUp if you've got any skill with hand drawing.
Open SCAD if you're good with coding languages.
Blender or Meshmixer if you're good at sculpting things.

Blender and SketchUp are the kind of software packages that a person can make a decent living out of using if they really build their skill with it. Sort of the way one can use Photoshop or GIMP to make a living doing graphics work.
Meshmixer and FreeCAD are more like MS Paint. They load in a snap, don't bog down on laptops and so are great with quick projects, but are highly limited on what they can do.

Thank you both for you replies, it's helped and I'll have a play with the Open SCAD as I'm a bit of a coder at heart. :)