Maker Shed has a new Microcontroller Comparison chart comparing six Arduino variants, the Raspberry Pi, and the BeagleBone.
I’m still amazed by the hobbyist wonderland that we live in these days — the number of choices, the capabilities, and the low costs are unbelievable.
For a nice introduction video to the Arduino series, see the descriptions at robotshop.com and the video at the bottom of the page.