Raspberry Pi Precautions
The Raspberry Pi is pretty robust; after all, it was built for kids. Even so, there are ways for things to go wrong. These are all in the Raspberry Pi documentation; I've but them in one place to make it easy to find the gotchas.
Please contact me at Bob.Brown@Kennesaw.edu if you find errors or have additions to suggest.
Plug in the power last: Connect everything else before connecting the power cable. That way, when your Raspberry Pi boots up, it will recognize the things connected to it.
Shut down before powering off: Just pulling the plug on a Raspberry Pi can corrupt the file system on the SD card and leave your Pi unbootable. Click the Raspberry logo in the upper left, select "Shutdown" and then click the "Shutdown" button before you remove power. Wait until the green light is off before removing power.
Shut down and power off before adding hardware: Shut down and power off your Raspberry Pi before adding hardware like different SD cards, HATs, camera, or add-on boards. It is generally safe for adults to connect things like LEDs to the GPIO pins with the power on. A mistake won't hurt you, but could damage your Pi. Younger students should probably power off before changing wiring, and check each others' wiring before powering on.
Watch out for static electricity: The Raspberry Pi is sensitive to static electricity. Consider using an anti-static bag for storage, and don't shuffle your feet across a wool rug when working on your Pi.
Don't break the SD card: The SD card sticks out slightly, and that makes it easy to break off. (If it didn't stick out, you couldn't remove it!) Unless your Pi is in a case, it's a good idea to remove the SD card and put it someplace safe before putting your Raspberry Pi away.
Let your Pi breathe: Your Raspberry Pi can generate significant heat. If you're using it without a case, or with the Coupé case in the shopping list, all is well. If you choose another case, be sure there's sufficient air circulation to let heat escape. You might even add heat sinks or use a case with a fan.
Be careful with the GPIO pins: It is very difficult to find a given pin by counting, and connecting the wrong one could fry your Pi! Use a GPIO reference guide that slips over the pins if possible. If you don’t have a guide, count carefully, then re-check.
Don't forget those resistors: Experiments involving LEDs and certain other components need a resistor in the circuit. Don't leave it out; its job is to protect other components by limiting the amount of current that can flow. If there's too much current, the magic blue smoke can escape. For LEDs, use the orange-orange-brown value, which is 330 ohms.
Resistors are not all alike: Be sure to use the right value for your purpose. If you're curious about those colored bands on the resistors, there's an explanation of the resistor color code in Wikipedia.