There are different software that will help you with 3D printing. These software are about 3D modeling, which smoothly make 3D printing.
Google SketchUp is a free and amusing program that is easy to use. Drawing models with SketchUp begins with drawing edges and faces with simple tools that can be learn within a very short period of time. With other tools in the software, it is easy to successfully create a 3D object in a digital file for printing.
3Dtin is a very simple 3D software. It is possible to directly draw from the browser.
Blender is a free and open suite, and its source contains 3D content. It is available for every major operating system that is under GNU General Public License. It is a powerful programs with features that characteristically have a high-end 3D software.
The OpenSCAD is a software that create solid objects that are 3D CAD. It is free and available for most operating software. It rather focus on CAD aspects than 3D modelling.
Tinkercad is an innovative program that quickly create designs for the 3D printer. With three essential tools, it is possible to create a high range of useful things. After the project is ready, the only thing remaining is downloading the STL file, and then start the 3D print.
These software listed above will make using a 3D printer possible and easy.