Circuit Design

Free Circuit Design softwares

Fritzing

An open-source program called Fritzing, which makes use of a nicely illustrated parts library to give the user a visual feel for how the circuit will look, as well as a proper schematic for each project. Download Fritzing at http://fritzing.org/

A simple step by step tutorial on building a circuit: http://fritzing.org/building-circuit/

Learn to program for Arduino along side Fritzing by watching videos at their youtube channel.

ExpressSCH

Another schematic drawing freeware software is ExpressSCH from ExpressPCB.

Paid Circuit Design and Simulation Software

Multisim from National Instruments lets you not only design a circuit, but also lets you simulate its behavior. Alas, it's not free.

Electronic Tutorial Videos at

http://www.afrotechmods.com/tutorials/

Online Electronics Tutorials at

http://www.electronicsteacher.com/tutorial/