Little problem - we have no textures. So, go to your NL folder (this is why its useful to have them close, saves faff) and copy and paste the files from the "teratextures" folder to "ObjTextures" inside the OBJ Creator file.
Creating your first ever modelOkay, lets start simple. Say for some random reason you wanted to place a cuboid inside NL.
Look for the graphed window labeled "Top". It should be the top right window.
Since I like being tidy on programs like this, to safe faff time later and to keep things clean, I like keeping to the grid.
So, click and drag out your shape. The grid on the far right tells you how tall your shape will be, I've set mine to 2.
As soon as you let go of the mouse, your shape is made.

Red means your brush (object) is selected, meaning after you make it you can move it about in the 3 axis. Pressing delete when it is selected deletes it, and the 3D window (top left) can be used to look at your creation 360 degrees. You move about much like in NL, right click to begin looking around, then hold the left mouse to fly about. WASD works to pan about. You can deselect by pressing escape, but don't do this yet.
TexturingTexturing is simple in Object creator.
With the shape still selected, press any of the texture images below, I chose grass. Your shape is now textured.
Note: if you add your own textures into the ObjTextures folder, they must be a "bit wise" size, ie 32, 64, 128, 256, 512, or 1024. The height does not have to be the same size, but it also has to be bit wise.
Exporting to 3DSOnce you've made your model and textured it, go to File -> Export -> Export to 3DS and save it in the "objects" folder in NL. You will have to place the texture(s) you used in there also.

Then in NL you can resize and move it around, remember:
Blue makes it scales bigger or smaller
Red, yellow and purple rotate along the XY and Z axies
Here is my model in all its simple glory:
Those are the basics. Play around with the shapes at the top:

The "?" lets you choose the number of sides (Max of 64)
The 3 buttons after let you choose in what way you want the shape to be 3d: a prism, a pyramid or a sphere.
And finally, the texturing and rotation toolbar (used only when a brush is selected):

From left to right:
3D move mode: move your model around in 3D space
Face Edit Mode: Hold CTRL and click the side of your shape you want to texture individually, used for things like signs when you only want the texture to appear on one face of the brush.
Edge Move Mode: Useful for simple adjustments if you get the size of your brush wrong but do not want to delete it. Escape to deselect selected edges.
Vertex Move Mode: More complex adjustment of brushes, lets you move the individual corners.
Undo: Exactly what it says on the tin.
Copy: See above
Select Brushes: When you want to select objects, you can with this menu. Shortcut: CTRL + click.
Deselect: Deselects all selected brushes.
Delete: Again, pretty obvious.
Then come the rotate controls, much like the way you rotate models in NL, but in jumps of 90 each time, it also has flip buttons.
And finally, Multiply brushes. Use this to essentially copy and paste selected brushes and move them to a position where you can adjust them later.
Thats about all there is to know about the Object Creator. Its about as simple as things get, but its not very powerful. The only way to learn how to do things
is to do them. Practice by making simple things, like a plant pot (A Cylinder), A lamp post (A bigger cylinder with a smaller one jutting out of the top, with a third at a right angle from the top of the second one) Do make whatever you feel like, then when you feel ready and want to make more complex things, like stations etc, move onto the next program.