Well said, and agreed. Actually, I completely agree with brlewis. "Learning" a language is a hard metric to measure. Accordingly, give a language/framework (if you are already familiar with the language) a couple of days, write a small app in it, and the rest, you will learn as you go.
IMO, in most cases, "learning" is merely trying to figure out how you would solve a problem within the scope of your selected toolset. The involves foreseeing what you will encounter down the road, which in a lot of cases is hard, if not downright impossible. Most books/tutorials (atleast the beginner ones) don't touch the boundary cases, so there's only that much value in them. That's not to say that you should drop every reference book on your shelf right now, but that don't spend a lot of time trying to master every detail before getting your feet wet.
Oh, and Good luck...!
2. Two days. (You'll learn as you go along.)
3. All other things being equal, use the language you already know. If things are unequal all bets are off.