I have some 18 inch wide pine boards recently milled to 3/4 inches. The boards themselves are about 25 years old and have been well stored. Lengths are 14 - 16 feet. I plan to cover an approx rectangle of 200 sf. I believe the carpet now present is on a plywood subfloor. these are square cut (not T&G) and I plan to lay them out and nail with old style square nails.

Sounds simple so where can I go wrong? Do I need a vapor barrier? any tricks for transitions with door ways? Relativley soft pine but a low traffic area for the most part. What's the best finish?

Thanks all.