Some may know of multisim. Well fritzing is a program I have gone to like. This is used to make pcb, pictorals, and schematic diagrams. This program is free and easy to use, it is a nice program to make projects on and to design your work on it. Multisim and fritzing are the two main programs I would recommend for engineers. Multisim will test out your circuit to show of functionality and fritzing will design it beautifully.

Links here:
Fritzing: http://fritzing.org/download/
Multisim: magnet:?xt=urn:btih:3909b6d58464f66c...nii.com%3A1337