Cherries or strawberries are ideal, because the stem provides a dipping handle—but orange slices, chunks of pineapple, large grapes etc., work well—just use a toothpick to hold them for dipping. For the holidays, sections of sweet mandarin oranges are festive.
Melt 4-5 squares from a bar of plain dark (at least 70%) chocolate in a small dish in the microwave on high. A minute or so should be enough. It will melt fast, so watch carefully the first time you do this. Do not let it go past melted, or it will burn.
Dip each piece of fruit in the melted chocolate and place it on a waxed paper-covered cookie sheet. Put in the refrigerator to cool and harden. If you’re in a hurry, put it in the freezer and it can be ready to serve in as little as a half hour.