finishing pine t&g ceiling??

[Diane Maluso]

A friend of mine is working on remodeling her house and asked me to pose this question. She's got cathedral ceilings and has insulated and sheetrocked. Over that she's planning on pine tongue and groove. So should she finish the pine before putting it up? Does she have to finish the backside? What finish/sealer is best? Methods? Any/all advice is welcome here since I've never done it and she's more clueless than me by far.

Thanks.

Diane