Printed Circuit Board Designer's Reference; Basics Chris Robertson
Publisher: Prentice Hall PTR

A secondary concern is radiated emissions. This isn't going to be a “how to use your mouse” tutorial. This will cause functional failure to the product and the safety of the users that are using the product will be compromised. Digital inputs/outputs — The key concern for digital interfaces is ESD. So here I'm going to tell you everything you need to know to make a schematic and PCB layout, and get a beautiful shield that will plug into the top of your Arduino. It is therefore critical for one to understand some of this basics requirements before one proceed to design the PCB. Prototyping breadboard, you can have a nice clean shield with labeled connections and a smaller footprint. The ability to easily and effectively separate sections of PCB boards can greatly reduce the design risks in systems that require sub-circuits of varying levels of noise generation and sensitivity. Thing: I assume you know how to use your computer. I'm gonna go with some things that are EAGLE specific, but you need to know basics. EMC Basics #5: I/O as critical circuits article gives some useful tips on the EMC issues related to inputs and outputs.