So far we know that it will be released in the second quarter. It probably can be purchased on most web sites that sell mobile devices. My guess is it will be a T-Mobile device for the US. So if that is true, it will be sold there as well. As for how soon it can be pre-ordered? No word yet... I would guess within the next month or so. But that is pure speculation.
I have been looking everywhere for the user manual pdf and not even a whiff. If someone finds it post a link here. With Best Buy doing presales, there should be a Manual.