Useful Resources
Member's Websites
Dale's Homemade Robots: Polyathlon, Mini Sumo, 1/3/12/30 lb Combat Robots, Balancing Robots, Vacuum Robots
Will's Robotic Adventures: Polyathlon, Mini Sumo, Protractor Sensor, Doppler Radar Sensor, Analog Line Follower
Charles Guan: EV's, Combat Robots, Drones
Keith Rowell's Biped Robot, Robot Mascot
Ben Axelrod: Robocup Rescue, Walking Robots
Eric Ayers: Bug Bot
Steven Easley: Mini Sumo, Line Following
Robot Brains
Arduino designs and sells open source microcontrollers for use in your projects. For beginners, the Arduino Uno is a great little microcontroller for learning how to write code that will run on your future robot. There is also the free Arduino IDE - a program you install on your computer where you write code, and then send the code to the Arduino microcontroller to run.
Arduino microcontrollers can talk to many types of sensor directly, but it's going to need some help if you want to connect some motors, add a screen, or other more interesting functions. Arduino "Shields" are add-on circuit boards that help an Arduino connect to all kinds of devices such as a Motor Shield, Sound Shield, or Touchscreen Shield.
Raspberry Pi is a pocket-sized computer than can run a full OS like Linux. It can't talk directly to as many sensors as an Arduino can, but it has much more processing power.
A Raspberry Pi can work with sensors and motors with the help of Hats - small add-on circuit boards designed for specific functions. There are lots of options for Hats, check out a few from our friends at Pi-Plates.
Robot Parts and Kits
Pololu sells great robot kits and their selection of motors and motor accessories for hobbyists is unparalleled. If you're building a Polyathlon, Mini Sumo, or other drive-around robot from scratch, you can count on ordering quite a few items from Pololu. They often have sales on major holidays in the US and their Black Friday deals lure us in every year.
Adafruit is best known for their variety of flashy LED modules and great selection of displays and other interfaces. If you're designing wearables, Adafruit is a great place to start. They have very detailed guides and high quality software libraries for their products and lots of project pages to get you thinking about your own next project.
Sparkfun sells all kinds of electronics and sensors for your robot projects. While Pololu and Adafruit design nearly all their products themselves, Sparkfun manufactures and distributes a good number of items designed by their own customers or other hobbyists in their community. Don't worry though, Sparkfun doesn't sell junk and is dedicated to providing support for all of the products they sell. Sparkfun also has an active blog and churns out high quality tutorials for those looking to learn more.
3D Printing
Prusa: Popular Hobbyist 3D Printer Manufacturer
RepRap: Open-Source 3D Printing
Thingiverse: Repository of 3D Models