First, take measurements for each wall and note the order for each panel. Since the oak paneling comes in 4x8 sheets, you'll be able to cover two panel sections at a time. In some cases, however, you'll be able to cut for a single panel. As long as the seams fall behind the stiles, that's all that matters.
Outside measure and cut the plywood for the height of the panels -- using a circular saw. Cut the plywood 1/2" shorter than the mark on the wall to give some play if the floor is uneven and can be hidden by the baseboard.
Work from the list and cut all the panels to width.
Whenever you're building a woodworking project, try to cut all the wood ahead of time so that when you begin the assembly you won't have to interrupt your thought process to go back and cut more wood.
When all the panels are cut, treat them with a stain conditioner (Image 1), which will help the wood absorb the stain evenly.
Note: It takes approximately 15 minutes for the conditioner to dry, so by the time you finish the last panel, the others are ready to stain.
Stain the panels by applying them with a good quality brush, following the grain (Image 2) and then wiping off the excess with a rag.
Begin by adding construction adhesive to the back of the paneling, and then place the panels on the wall, making sure to keep the top edge lined up with the top horizontal lines marked off the floor (Image 1).
Once the panel is in place where you want it, use a brad nailer to secure it to the wall (Image 2). You can place brads everywhere the stiles will be located since they'll be hidden.
When you come to a panel that has an outlet in it, remove the cover plate, and then measure over from the edge of the first panel to both sides of the box. Do the same from the top and bottom of the box.
Note: You'll wait until this point to cut out for these boxes because the holes need to be place accurately.
With the power "off" loosen the outlet itself so you'll be able to get the panel on after the hole is cut.
Take a quick trip back outside to cut the hole for the box using a jig saw. Once that's done, test fit the panel to make sure the cut is exactly right (Image 3).
Add adhesive to the back of the panel and set in place, and nail it inside the markers for the stiles. The panels go up easy so just continue around the room.