Now it's time to measure for the stiles. Each one must be taken separately since they may vary a little -- and they need to be custom fit.
Take several measurements at once, and then cut them to their proper lengths.
With that done, rout the "female" ends on the stiles using the router table. Then go back inside to install them.
Set a stile in place, add one nail and check to make sure it's plumb -- then secure it to the wall. This covers all the seams where the oak paneling meets.
Use the guidelines that were drawn earlier on the wall to line up the stiles in their proper locations. Since the stiles were pre-cut, they should go up easily.