This is the technique to fit Dado rails made of timber. It is quite easy and can be done yourself thus saving a lot of money in the process. First measure the distance of the wall and make marks to position the rails. Cut the dado to fit this size. Then level the dado against the wall with a spirit. Check out that the dado is level by drawing a line under it. Now stick the dado rail to the wall with a suitable adhesive and use a nail to gun it properly in position.
Your dado rail is ready. If you want detailed instruction made easier with illustrations then look at the site at www.iafrica.com. You would also get the addresses of the suppliers of Dado rails from this website. You can get easy instructions on many more things from this website.