Hanging drywall

Hang drywall horizontally if at all possible. Try to put the joints centered above or below windows or above doors. The horizontal seams are MUCH easier to do than vertical seams. My last project with 110' of walls had only 14 total feet of butt joints, all in out of the way places. If you have drywall finished ceiling, put the ceiling in first, you can leave small gaps at the edges to make it easier on yourself. The put the first row of wall material up snug to the ceiling. Put the second row in at the bottom, leave the uneven gap at the floor.
Sounds like you have 12' walls so 3 rows of drywall. That means every 4' of vertical placement will give you 12' of tapered seam. Running it horizontal will give you 8' of horizontal tapered seam (much easier to tape) plus some part of some butt seams.
stryped wrote:

AMEN! My last job involved 4-1/2'x12' sheets to deal with a high ceiling. 104 pounds each, the 12 footers need to be taken off the truck in pairs. I got REAL TIRED of the 204 pound wiggly chunks of rock!

For your size I'd go with 4X16 and stagger the vertical seam (but joint).

If you're going to hang it parallel to the studs, why would you even think about using 4x12 for a 10-foot wall? What's wrong with 4x10???
Unless you have a capable helper, don't even consider using anything longer than 4x12. Even that can be a b*tch to handle. 16 is way too long for one inexperienced person to manage.
Either 4x10 vertically, or 4x12 horizontally. Heck, do one wall one way, and the opposite wall the other way -- then you can decide which one works better for you.

Yeah, but his story about it might be amusing...