I jost noticed this post,
I also have a pine floor, I sanded and stained mine just before xmas. be carefull with a sander. I 1st uesed a drum sander with 20 grt. and it left ridges in the wood, after going threw 3 other grades or paper I still had the ridges. ended up renting a rotery sander, (big ass floor scruber) with sanding screens. If I was to it again thats all I would use.
Then I stained it, 3 coats poly, 6 coat poly floor wax. looks great.