Depends on the size and layout of the house surely? Along with how many bikes and which one(s) need to be easily accessible for daily commuting vs only used at weekends.
We've got a big kitchen with hardwood floors so it's easy to store them to one side out of the way of food prep. Spares, tools, tubes etc all need ruthless control otherwise they tend to take on a life of their own and spread all by themselves. Got a small plastic box on the fridge for easy access and then a toolbox in an out-of-the-way kitchen cupboard that's too inconvenient for any food / utensils. Between us both, it seems to work.
I have in the past (in a previous house) kept a bike in the bedroom but I'm not a fan of it - no matter how much you clean it, you inevitably end up with road grime inlaid into the carpet unless you put rubber mats everywhere or have hard flooring. Plus carrying them up and down stairs is a pain.
When I was at uni, I used to clean my bike in the communal kitchen (it being the only place in the student flat that had lino floor). Initially, my housemates weren't happy with that but then they realised that it was the only time the kitchen floor got swept!
If you go down the option of getting a shed, make sure it (and/or access to your garden) is very well secured. Takes seconds to get through the walls or roof of most sheds - securing the door simply means that the roof will get pulled off. You can get (quite expensive, but much more secure) specific bike storage units: [www.asgardsss.co.uk