What's it like to have a well/septic instead of city hookups?

I’ve always lived in places that are hooked up to city water and sewer systems. However, we’re looking at places in the country that only have a well and a septic system.

I understand, in general, what they are, but I would like to hear more about what it’s like to live with them. For instance, do these things have to be maintained often, and/or at great cost? What happens if your well runs out of water? How does a power outage or freezing weather affect them? What are the inconvenient things about them? Are there limits to what you can do to the land above the septic area? Are there pros and cons that a city girl ought to know about? What do you recommend?

Thanks!