Fritzing is a free, open source program for designing electronic circuits and schematics. It includes breadboard simulations, schematics drawings, and PCB design. Its users have created a large library of electronic components, including Arduino models, so that adding components to your design is often as simple as drag-and-drop.
Fritzing is open source software, anyone can download and install it for free on their personal computer.
Install Link: http://fritzing.org/download/
Tutorials are available at http://fritzing.org/learning/.