http://3exposure.com/2011/06/10/better-360˚-panoramic-photos-using-photoshop-automation/
or just keyword search 360 panoramic for photoshop - or lightroom or gimp or whatever you want to make it in.
Pano2VR, version 4 pro make tours easy, but it's too expensive for me. I'm still on version 3, tours still possible but rather more trouble.
http://ggnome.com/
Don't know of any freebies.
I think you'll just have to take lots and lots and lots of images while remaining in the same spot, turning your hip, rather than moving (you'll need a good back!) as for the floor, probably would have to clone out the feet, theres no way of floating in mid air, unless you've got a magic carpet?So how do you get the roof and the floor in?
So how do you get the roof and the floor in?