Home generators during power outages

So coworker and I were talking about this. Sharing our experiences during the last disasters to hit us, we got to talking about generators.

Assuming I get a gen from the home store, that i place outside, runs off of gas/propane, what is the actual method of powering needed stuff? Medical devices, fridge, etc.

I know gens has a port for the high voltage so do we run ext cables through the window? Wiring the house is also an option but expensive for the initials setup. What do people generally do?