Autodesk 123D Circuits

Electronics from beginner to pro

123D Circuits empowers you to bring your ideas to life with free, easy to use online tools. If you are a beginner, you can start with simple experiments in the Electronics Lab or Circuit Scribe. Experienced users can skip ahead and go straight to PCB Design.

This site also allows you to have your designs built for a price. 

Adafruit

Adafruit was founded in 2005 by MIT engineer, Limor "Ladyada" Fried. Her goal was to create the best place online for learning electronics and making the best designed products for makers of all ages and skill levels. Adafruit has grown to over 50 employees in the heart of NYC with a 15,000+ sq ft. factory. Adafruit has expanded offerings to include tools, equipment and electronics that Limor personally selects, tests and approves before going in to the Adafruit store.

SparkFun

SparkFun is an online retail store that sells the bits and pieces to make your electronics projects possible. No matter what your vision is, our products and resources are designed to make the world of electronics more accessible to the average person. In addition to products, SparkFun, through our Department of Education, offers classes and online tutorials designed to help educate individuals in the wonderful world of embedded electronics. Our ever-growing product catalog boasts over 3,500 components and widgets designed to help you unleash your inner inventor.