The job of putting up a new wall ranges from simple to complex, depending on where the wall will be located. The determining factor is whether the wall runs parallel to the ceiling joists or whether it cuts across them. Walls are usually attached to the joists above, so a wall that goes across the joists is easier to build. This is because the top plate can be nailed through the ceiling to the joists.
Building a wall that runs parallel to the joists is somewhat more involved. Unless you are lucky and your wall falls directly under a joist, you'll have to open up the ceiling to install blocking to attach the top plate. In fact, if moving the wall an inch or two would place it under a joist, consider doing so.
If you are attaching a top plate through a plaster ceiling into joists, predrill the plate and attach it with 3-inch wood screws.
About 1 hour for a simple wall that's perpendicular to the joists
Tape measure, chalk line, hammer, circular saw, power drill/driver, utility knife, layout square
Measuring, snapping a chalk line, hammering, crosscutting
Complete remodeling plans
2x4 for top plate, 16d nails
Use a handsaw or reciprocating saw to cut away the ceiling flush to the inside faces of the joists where the wall will attach. Snap a chalk line along the center of each joist, then use a utility knife to cut away a 3/4-inch-wide strip of drywall. This will expose surfaces on the joists for attaching the new drywall.