I put down white oak 15 years ago and used Varathane water based gloss. (Chose this over solvent based because those are said, even by the manufacturers, to go slightly amber over time). Put down two coats with the recommended applicator, then fine wet sanded before the final coat. Very little smell, dried fast and looks great even today.
The water based does stay water clear. The oil based will amber over time.
If you don't like the amber, stick to the water based, but understand that the water based has a lower solids content, so does not wear quite as well.
Oil based urethane needs a full 24 hours between coats. Water based can be recoated in just a few hours. For that alone, a lot of installers prefer it, because they can get off the job faster. Oh, and water based has much less odor.
I used Varathane (oil based) on my oak stair treads. I do not believe that the finish is fully hard for 30 days. That said, after babying the stairs for a while, they are holding up damn well. Better, I think, than the factory finished wood floor.
Yes. You shouldn't put ANYTHING on the floor for 7 days, and walk around in socks. Then be extra careful for the first month or so.
Some pointers:
When you're ready for the first coat, vacuum the room. Then go over everything with a tack cloth. As said above, you'll be amazed at the number of hairs you pick up.
The first coat should be a wax free shellac sanding sealer. This soaks in quickly, hardens the wood for a more durable finish, and dries in 30 minutes (that's how fast it is ready to recoat). It'll also stop the first coat of poly from completely soaking in.
If you want a finish other than gloss, I'd suggest you use gloss for every coat except the top. What makes the satin finish, is a powder added to the mix that dries under the surface. It looks better when you don't have this in every coat.
Sand in between every coat. A random orbit sander is best for this. I actually have a U-Sand machine which makes the job real easy. The foam backed sanding pads are great between coats.
Be absolutely sure to clean out the dust collector bag on your sander after sanding recently dried oil based poly. The poly gets hot as it cures, and a full bag of curing dust can start a fire.
I used a sheepskin mop to apply the poly. You work a "wet edge" in the direction of the grain. WASH the mop in whatever thinner is to be used with the poly before using it, to get out any stray hairs. Or, if you have a compressor, just blow on it with air.
For spots under radiators where the mop wouldn't fit, I cut a triangle out of a paint pad, and stapled that to a piece of wood cut at an angle.