How to Install and Setup EAGLE
jimblom 
Introduction
Printed circuit boards (PCBs) are the backbone of every electronic gizmo out there. They're not flashy like those microprocessors, or abundant like resistors, but they're essential to making all components in a circuit connect together just right.
We LOVE designing PCBs here at SparkFun. It's a love that we want to spread. It's a skill that benefits electronics enthusiasts of every caliber. Through this and a series of tutorials, we'll explain how to design a PCB using EAGLE -- the same software we use to design all of our PCBs.
This first tutorial goes over how to install the software, and tailor-fit its interface and support files.
Why EAGLE?
EAGLE is one of many PCB CAD softwares out there. So you might ask: "What makes EAGLE so special?" We're fond of EAGLE for a few reasons in particular:
- Cross-platform -- EAGLE can run on anything: Windows, Mac, even Linux. This is a feature not too many other PCB design softwares can boast.
- Lightweight -- EAGLE is about as svelte as PCB design software gets. It requires anywhere from 50-200MB of disk space (compared to the 10+GB more advanced tools might require). The installer is about 25MB. So you can go from download to install to making a PCB in minutes.
- Free/Low-Cost -- The freeware version of EAGLE provides enough utility to design almost any PCB in the SparkFun catalog. An upgrade to the next license tier (if you want to make a profit off your design) costs at least two orders of magnitude less than most high-end tools.
- Community support -- For those reasons, and others, EAGLE has become one of the go-to tools for PCB design in the hobbyist community. Whether you want to study the design of an Arduino board or import a popular sensor into your design, somebody has probably already made it in EAGLE and shared it.
Of course, EAGLE has its drawbacks too. More powerful PCB design tools out there might have a better autorouter, or nifty tools like simulators, programmers, and 3D viewers. For us though, EAGLE has everything we need to design simple-to-intermediate PCBs. It's an excellent place to start if you've never designed a PCB before.
Recommended Reading
Here are a few tutorial and concepts you may want to familiarize yourself with before dropping down into this rabbit hole: