3500W generator I picked up

Is that an invertor type generator? If not, you need to be careful running sensitive electronics off of it- make sure computers/tvs etc. run through a surge protector or some sort of line conditioner to make sure they play together happily. People forget about things like high efficiency furnace controls, microwaves, etc. that can be sensitive.
I would look into some kind of indicator light on your main panel to let you know when your power comes back on so you can shut down the generator and flip your main breaker back on.