It depends on where you are laying the tile. If it is in the shower or wherever there will be water present, such as countertops then you must use greenboard, concreteboard or backerboard unless you are laying it on top of an existing non-porous surface.If you are laying it over laminate, then rough up the surface a bit with a palm sander. If you are laying it on a concrete floor then you " have" to use" thinset". You can buy and mix it yourself or use the premixed. Home Depot carries one called gray premixed for floors, walls and counters. It has a yellow number 1 on it that says spread and set.If you are tiling walls you can use tile MASTIC. It is a white tile adhesive that is easier to work with than the thinset. I prefer using it on walls and countertops. You can also pick up a little pamplet in the tile section of Home Depot that will give you the basic instructions on the proper way to lay tile and which size spacers to use with the tile size you pick.. It's really not that difficult. If you are going to use spacers to lay the tile, I say, do yourself a favor and get the more expensive type instead of the rubber ones. You don't have to dig them out from between the tile. They sit on top of the corners to ensure that you get the tile lines straight and level. Some of the smaller wall and countertop tiles have notched areas on the sides for spacing but I think a 6x6, 8x8, up to a 10x10 inch tile looks good on countertops. The lines are smoother cleaner looking. It doesn't look so busy looking. Also using a grout that is close to the color of your tile makes the end result look more professional. Make sure you get the right size notched tile trowel for the size tile you are using.