1) Buy a pineapple from your local store. You should looke for one where the crown of leaves is fresh and green, with no dead or damaged leaves. In addition, make sure there is no gap in the centre of the crown (means the grower has already plucked out the gorwing core)
2) At home, gently twist off the crown of leaves. It should come away fairly easily, leaving a ragged stump (plus the fruit, which you can eat in the normal way).
3) Start to strip off some of the lower, outer leaves at the base of the crown by pulling downwards. They should come off like you'd peel leaves from a cooked artichoke. You want to expose about 2-3 cm of base. As the leaves come off, you may see some rootlets.
4) At this stage, you need to let the stump dry off for a week or so, otherwise it may rot or not develop properly. After this time you can treat the pruned crown like a cutting.
5) Pineapples seem to grow best in a mixture of sand and compost - suggest 50:50. I don't believe its necessary to use rooting compound (though it may not do any harm) as the crown normally contains embryonic roots anyway. Fill a small-med pot with the above mixture, make a small central hole and push the crown stump into it so the whoe base is buried up to the first set of leaves. Make sure the crown is stable & doesn't wobble about.
6) At this point, you should put the pot somewhere light & warm but not in direct sunlight or with extremes of temperature. Whilst you're waiting for the roots to develop, the crown may dry out or yellow. With all of mine, I've put a clear polythene bag over the crown, to help retain moisture (you may wish to do this during stage 4 if your initial attempts down survive well).
7) From here, you may have to wait a month or so (sometimes longer) before you see signs of growth. This may depend on the conditions and also the variety of fruit you've bought. During this period, check regularly (especially for mould, mildew etc if you've got a plastic bag over the crown). There's no need to apply water, other than to ensure the sandy soil doesn't dry out completely.
8) Finally, you should see some new leaves emerging from the centre. You can remove any bag at that stage, though be careful not to dislodge the crown as it will take a while for a good root system to develop. Below, you can see a selection of young pineapple crowns. The one on the right shows some emerging leaves, whilst the others are less well developed. Click on the thumbnail to see a bigger image:
