Quick! Turn back NOW!! It's a trick! It's not an Instructable! It's a science lesson!
O.K. Not to be dramatic, but electricity, and all things electronic, have a lot to do with science, and although this tutorial will contain science, it will also have hands-on examples.
Have fun learning how electricity is made, and how you can make electricity!
Note: This tutorial is for beginners. I am not an expert, and I'm sure there are many Instructable members who now more about this than I do about this subject. That said, I hope this tutorial can help you learn in a few minutes what it took me several years to learn. (I can be a slow learner sometimes. :-)
Step 1: How It Works
Imagine the copper wire as the ditch, and the electrons as the water. Copper wire (a.k.a. "ditch) contains electrons (a.k.a. "water). When a magnet (a.k.a. "water wheel) spins around inside a coil of copper wire (a.k.a. "ditch"), the magnetic field (a.k.a. "the water wheel's force") pushes the electrons (a.k.a. "water") forward, thus creating electrical current (a.k.a. "the water wheel turns).
If I haven't confused you yet, there's more! The above-described method is not the only method of generating electricity. In fact, there are piezo-electric discs, peltier tiles, chemical reactions, etc... I will not describe these methods for the sake of simplicity(and for lack of extensive knowledge on my part).
Note: This is a simplification of the process, not an exposition.
Step 2: How to Do It
Pictured above is a hand-crank generator that came from a kid's electronic set from a thrift store. Up to this point you may be clueless as to why turning this generates electricity. The answer is simple. If you feed electricity into a motor, you'll have a motor that turns, but if you turn the motor shaft, it forces electricity out of the motor instead. That said, to generate electricity you can spin the motor shaft and it will move electrons out through the wires.
Note: This is still a simplification of the process, not an exposition.
Step 3: Make Your Own
To make your own generator, you can salvage a motor from an old fan, treadmill, etc..., and spin the shaft. This works sometimes, but not always. Sometimes a diode, or an electronic piece that prevents reverse flow of electricity, keeps it from generating.
In an emergency, you can find a source of copper wire, such as an old speaker, motor, etc..., and a source of magnets, such as an old speaker, motor, etc..., and combine the copper wire and the magnets, to create a motor/generator.
Thank you for reading, and I hope you learned something from this tutorial!
Please comment with better descriptions of the processes, and correct me if I'm wrong on any of my basic scientific principles. Thanks!