Blender: figuring out how to create a 3D object

For the last year, I've been realising that I need to learn how to create objects for 3D printing. It feels like it'll be a useful skill within about 1-3 years.

Step 1: Find out what file type you use for 3D objects. Google tells me that they're .obj and and .stl files.

Step 2: Find an open-source programme to create 3D objects. I've chosen Blender.

Step 3: Install and boot up Blender 2.69 ...

Step 4: Try and figure out how to do something. My first two goals will be to rotate the camera and to change this starting square object into a sphere.(*)

(*) This is one of my favourite parts of the learning process:

seeing an overwhelming number of buttons and options, 

and gradually making sense of them.

My experience with teaching myself GIMP and Scribus is that whatever you google for, there's usually a tutorial.

So, after googling I immediately learn that:

• TAB changes the menus on the side of the screen from 'Object Tools' to 'Mesh Tools'
• You can select all the vertices of an object by pressing 'A' (and I've learned that the idea of 'an object's vertices' is important)
• ... and I've learned that there's a 'To Sphere' button somewhere on this screen but that I can also 'sub-divide' the object 100 times.

I can't immediately find the Sphere button, but pressing sub-divide seems to freeze up the programme. After it recovers, I set the smoothness of those subdivisions to '100', which totally explodes the screen:

So, that's not the way. After rebooting my computer, I try it again with different values for smoothness, but sub-division just seems to create a bunch of different spheres bulging out of the original one.

Doing this, though, I learn how to drag the object through 3 dimensions:

• click on the blue/green/red arrows in the centre of the screen
• drag the cursor left/right and up/down

Time to find a new tutorial. This 'Build a penguin' one looks like it has some good info.

And success! Pressing SHIFT-A > Mesh > UVSphere creates a sphere I can drag around.

That Mesh menu has tonnes of options, including 'Circle. I wonder if I can create layers of it, to build a disc?