Where to start with modeling?

[jimc]

you can either love sketchup or hate it but what its not good for is making models for 3d prinitng. sketchup isnt a solid modeler. its a surface modeler. perts exported from sketchup usually have issues for 3d printing. many can be correctled with a quick run through netfabb but some cant. there are so many pieces of software out there its not funny and like what was mentioned before you need to know what type of modeling you are going to be doing. sculpting type stuff or mechanical stuff. blender and zbrush for instance are for organics and more of a sculpting type where freecad, rhino, solidworks, etc are more engineering or consumer products.

[Apollo]

Also, if you're looking for an extremely easy way to learn, one with guided lessons and such, take a look at TinkerCAD (its free). Some people scoff at it for being too simple, but it is very effective at teaching basic CAD concepts that you will use no matter what program you end up using. I used it to break the ice with CAD modeling, and it really helped me with usingFreeCAD. As an added bonus it even exports .STL files that are ready for you to print!

https://tinkercad.com