Should be toe up half way back, dependent on your grip knuckles will vary. Here is good little drill, on take away half way back, club parallel to ground, you should be able to turn 90 degrees, (whole body, feet and all) without moving the club position you set, now drop the club to the ground, you should be pretty much in the same position you were at address, this is what is meant by clubface remaining square on takeaway and a one piece takeaway.

If you are rolling your hands or shuting the face or laying the club off during takeaway, you will see this immediately when you turn 90 degrees and drop the club, it will be way, way off from the address position. This is just a drill and check point, obviously you can't hit balls this way