Have been to 10+ Twins games since this place opened and it impresses me every time. The view is good from everywhere, where to sit should be all according to your preference really. 239 was on the Grandstand which are the upper deck seats in right center field. There weren't too many seats in our row but the climb to the top is a chore. For safe measures, avoid any rows in the teens because the entrance/exit tunnel is way at the very bottom near row 1. Row 1 is obviously the seat you will want to have in this section so you can lean over and see every bit of the field down below.

If you've ever sat on the home run porch in left field, the Grandstand is the equivalent but in right field. On the home run porch you get the view of the skyline but can't see scoreboard. In 239, you get the view of the scoreboard but can't see the downtown skyline. Like I said, where fans sit is all according to preference.

The quickest access point for the Grandstand would be to enter Gates 34 or 29 and take an immediate right upon entering. The promenade area is beautiful out there, plenty of space to move around and mingle with all kinds of other Twins fans.
Target Field is still shiny and new three years later. It's going to be home to the Twins for many, many more years to come but that doesn't mean that you should delay your trip here.