Question

What are the input and output structures of a neuron and where is the action potential generated?

Answer 1

Here, this Kahn Academy video will help: http://www.youtube.com/watch?v=ob5U8zPbAX4

It's pretty short (a bit more than 6 minutes) and it explains neurons much better than I ever could.

Answer 2

You can check out the other neuron-related Kahn Academy videos too to get more information. There's another one where he explains how signals are actually transmitted (with diagrams!).