Interlock Kit is about the most affordable way for a handy person to properly hook up a generator to an electrical panel.
You buy the specific silver slide tooling for your panel. Remove the panel cover. Drill and install the mechanism and then it prevents you from having your main or your gen breaker on at the same time. So you can't back feed the main line and the main line can't back feed the generator when the power comes back on. Gens are rated at 30 amps. So install a 220V 30 amp breaker in the top position, run 30 amp wire (usually orange/purple), 4 wire red white black bare, hook it up in the panel, drill a hole through the wall, run a wire to the outside, and put in a 30 amp generator receptacle. Make up a 30 amp extension cord (wire and both ends rated at 30 amps, everything 30 amps!) and you are off and running. Make the extension cord 4 wire too and the ends 220 30 amp plugs. Use a generator with a 30amp 220v outlet with four plug holes / posts. (thats the red white black and bare)
The draw back is it doesn't do the automatic start thing. But they make a remote start generator that can be hooked up and all you have to do it throw the breaker and hit the start button. (That way someone can do it while I'm away.)
((they make gens that are tripple fuel use options too, Diesel, Gas, Propane.))
If you have a barn or an out building far enough away from the house that's safe for running the generator in I suggest putting the gen outlet there and installing emergency lighting in that area that comes on when the power goes out.
(Out in the barn you can run a 50amp circuit instead of 30 amps to allow for a bigger "barn" generator.)
(make sure gas carbon dioxide can't go down the conduit to the house or something crazy, not that I am recommending that you do this or anything.)
For entertainment purposes only.
https://interlockkit.com/about-us/