First of all, start with a pineapple. Cut off the top and remove all the flesh around the bottom of the leaves (otherwise it will rot) Then remove some of the bottom leaves. I have found some pineapples that already have some stringy looking root things or at least little buds where the roots will start from. Unfortunately none of them made it for me. Then let the stump dry for a couple days. At this point you need to stick it in water to form roots. I suspended mine in a clear, blue glass with toothpicks stuck in the leafy area. You don't want the leaves in the water or they will rot. Change the water every other day if at all possible! In a couple weeks you should get roots! I left mine in the water for another week to let the roots grow some. So, here is what it looked like the day I planted it.
Top plant it I started with an 8" clay pot, an extra a saucer to break and place in the bottom, some cactus soil, and some perlite, First thing is to break the extra saucer and place it over the drain hole in the pot; not to completely cover it but at an angle to allow drainage.
Then mix 2 parts cactus soil and 1 part perlite. I just do this in a large bowl by dumping in 2 cups of soil and then 1 cup of perlite.
Add some of the mixture to your pot, followed by your pineapple, and finish with the soil mixture.
Water thoroughly and place in a sunny location. It will need watered once a week. You never want the soil to be super wet though, or it will rot. After a couple months you can pull on the plant to see if it is viable. If it resists you tugging it has formed new roots, but if it pulls out then it died. Obviously my new one isn't that far yet, but I will update when it is. Here is a picture of the new little one with my bigger one that was repotted in March. I think it may actually need repotted again soon.