Installing Wainscoting
The paneling is quarter-inch hardboard with a white laminate over it (like formica, but thinner). It's the kind with pairs of "pinstripe" grooves about 1.5 inches apart, sometimes called "beadboard." (To be specific, the paneling I used was Georgia-Pacific Jubilee White Ice.)
It comes in 4x8-foot sheets, with the grooves running lengthwise. So, you'll make cuts across the shorter dimension of the board to bring it down to the desired height. We made ours 42" from the baseboard, or about 45" from the floor. Have the home center make the cuts for you; it's usually free, and it's much easier for them to do it on their panel saw than for you to try to do it with a circular or table saw.
You can use glue, nails, or both to hang this stuff. We used a solvent-based drywall adhesive (we're attaching it to drywall), with a few nails to hold the panels in place while the glue cures. This has the disadvantage that it's going to trash the wall if we ever want to take it down, but not using glue would've required many unsightly nails.
You can abut the paneling to the baseboard molding, or remove the baseboard molding (if any) and put it back on over the bottom of the paneling when you're done. We left our molding, because it was a two-part molding with a quarter-round shoe molding, and would've been a lot of work to remove and then reapply. I recommend you remove the baseboard molding! It will look better, the baseboard molding will hide any gaps between the paneling and the floor (see below), and it'll be easier to install the paneling.
Contractors have a saying regarding houses: "There is no such thing as a right angle." So true. Our walls aren't quite plumb, and more critically, our floor isn't quite level. The right way to hang paneling is to find the highest point on the floor, mark the height you want your paneling at that spot, and then snap a level chalk line around the room at that height. Then hang the paneling so its top edge is at this chalk line. I didn't do that. Worse yet, I did two walls simultaneously, meeting at a corner, and since the floor isn't level, they ended up meeting about 3/4 inch off. Luckily, my cap molding covered this up, but just barely. Furthermore, there's a gap on one end between the paneling and the baseboard molding that it is supposed to abut; again, this gap would have been covered by the baseboard molding if we'd taken it off and put it back on over the paneling.
Since the substrate is brown hardboard, and the seams are supposed to be a dime's-width apart, you are left with rather obvious dark lines at the seams between panels. We solved this by filling them with white caulk; the caulk will expand and contract as the panels do from changes in temperature and humidity, but it visually fills in the seams.
If I did this project again, I'd consider using the ready-to-paint style of paneling instead of this laminate. You have to paint to touch up the nail holes and whatnot anyway, and since the laminate is so glossy, the touchups don't quite match. And you have to paint the cap molding and possibly the baseboard molding too. And finally, the laminate surface is quite thin, and already in a couple of places I've accidentally scratched it through to the brown hardboard substrate. So, next time I'd probably use the ready-to-paint paneling, and paint it, the cap molding, and the baseboard molding all at the same time when it's all installed.