I have to interject this tip.
I recently completed a very large interior stain & 2-coat poly job. I had incredible results using Zinser's newest sealer, Seal Coat. It's alcohol-based shellac (fumey) but it contains
no waxes, (like sanding sealer does), so it dries very quickly and creates a film over the wood as a good base for the poly-u.
The best part was the finish: the faster dry time created almost no raising of the wood grains, so there was very little sanding to be done. This meant less sanding dust/residue. When the poly-u coat went on, it stood up with a very nice, deep sheen!
Also, it cost me roughly 5-6 bucks less per gallon than polyurethane.
If you can get by the fumes, it's a good base for your poly job.
Mac