What safety precautions should I observe when handling electronics?

Make sure it’s unplugged, for one. I don’t think that a fan would have much of a static charge to it, but if ever you’re suspicious, try grounding it out with an insulated wire or something. I don’t expect that you’ll find any nasty chemicals inside of most household electronics (unless it uses a refrigerant, like a refrigerator), but if you do, look up the Material Safety Data Sheet for it for guidelines on cleaning and disposal.

Just make sure you’re grounded, usually with a safety strap. This is more of a precaution for the components than it is for you.

The only “nasty chemicals” would be found in batteries and electrolytic capacitors. Everything else is pretty benign, materials-wise. Be careful around power supplies as the filter capacitors (cylindrical in shape) can store enough of a charge to give you a shock even with the device unplugged. A fan wouldn’t have such a power supply, though.

If the equipment is unplugged then you won’t be at risk for electrical shock (except for warning above). Being well-grounded makes you MORE susceptible to shock if the equipment is still plugged in—think barefoot in the bathtub, which is a condition of being very well-grounded. If you’re worried about electrical shock, wear rubber-soled shoes and keep one hand in your pocket!

The biggest risk to the electronics is with static electricity from you. A fan shouldn’t have any microelectronics in it.

The biggest risk to you is from capacitors that store thousands of volts. The dangerous ones look like big cylinders. Don’t touch those. But now that CRT displays have become dinosaurs, not too many things use big capacitors any more (though power supplies do and some big stereo power amps).

And most important, ask your parents before you start dismantling household appliances.

A fan? Probably no ‘electronics’ in that. A motor and some a switch or two. A fan motor is pretty innocuous. The worst thing you’re likely to encounter in a fan are the lubricants on the motor bearings.

A household fan is not a bad place to start, though. If you can get that all apart without having to break something you have earned your first tinkering merit badge. If you can put it back together and it works as well as it did before you get an extra one.

In the long run this pasttime requires some tools that kit is way overkill but you get the idea. Screwdrivers of multiple sizes and types. If you’re taking apart any Apple equipment you’ll probably need star drivers.

If you are working with real electronics (something with a control system) @CaptainHarley‘s suggestion of a grounding strap is a top priority, get one. Go to a local Radio Shack and check out the kinds of tools they have there. And as elsewhere noted make sure the thing is unplugged and look out for capacitors. If you don’t know what a capacitor is, and what they look like, find out before you pop open any electronics that ever plugged into the wall. Leftover charge in a capacitor can actually kill you, not likely but don’t test the possibility, ok?