Turn off the power to the kitchen and then remove everything that is on the wall, such as outlet covers, switchplates, and any other item in the area that is to be tiled. Then clean the surface thoroughly to remove any grease or other debris and tape off the area.
Plan your Layout
Lay out your tile horizontally below the wall where you're going to place it. This makes it easy to ensure that your pattern will fit in the space provided. Also it helps you double check that you have enough tile and know exactly where each piece will go.
Spread the mortar on a small section of the wall with a trowel. Thinset and other adhesives set quickly so make sure to work in a small area. Once it's applied, comb over it with a notched trowel.
Add your tile to the wall
Place the tile sheets along the wall, making sure to add spacers so the tiles remain lined up. Press the first piece of tile into the wall with a little twist, leaving a small (usually one-eight inch) gap at the countertop to account for expansion. use a rubber float to press the tile and ensure it sets in the adhesive. Repeat the mortar and tiling until your wall is completely tiled, working in small sections.
Apply the grout
Allow the thin-set mortar to set. This usually takes about 12 hours. Don't mix the grout before the mortar is set, because you don't want the grout to dry out! To apply, cover the area thoroughly with grout and make sure you fill all the joints by spreading it across the tiles vertically, horizontally, and diagonally. Then fill any remaining voids with grout.
Then, with a moist sponge, sponge away the excess grout and then wipe clean with a towel. For easier maintenance in the future, think about applying a grout sealer.