Anatomy of a Wall Frame
The frame for a wall can be various dimensions. Nevertheless, the basic structure is always the same. It has two "plates", the top plate - a 2X4 running horizontal along the top of the frame, and sole plate - another 2X4 running horizontal along the bottom of the frame. Then, spaced, usually at 16 inches on center, vertical studs.
When we talk about 16 inch on center, we mean that from the center of one stud to the center of the next stud is about 16 inches. The studs are spaced this way to accommodate 4X8 foot sheets of drywall or paneling. Note, however, that the first 16 inches are measured from the edge of the plates.
Our diagram shows a wall 4 feet wide. Generally you will be making wider walls. You can get 2X4 lumber at lengths up to 16 feet. Depending on the width of the wall you are building, you may wish to make your plates ten feet, twelve feet, or even longer. To keep the frame from getting unwieldy during the construction process you may make several frames and string them together. If you are framing a corner, you will want to put two studs on the longer frame end where the corners are to meet.
With this information, you should now plan out your partition. It is best to draw it out on a piece of graph paper so that you can get a good estimate of the materials you will need. The wood does not need to be prime grade lumber. Remember that it will be covered by some material. Even so, when purchasing your wood avoid twisted and warped pieces. It is also wise to get a couple extra 2X4s. You will inevitably find a need for them, if not on this job, then on the next. Don't forget to pick up a decent quantity of 10D nails. You will need at least two for every place where wood meets wood. It is also wise to have a few extra nails.