Molasses: Although it is primarily used for flavoring gingersnaps and gingerbread, molasses -- a thick, dark brown syrup generally made from the juice pressed from sugarcane during refining -- adds sweetness to baked goods, too. Molasses comes in light and dark varieties. The two forms are interchangeable, so choose one depending on how much molasses flavor you like.
Brown sugar: Brown sugar is a processed mixture of granulated sugar and molasses which gives it its distinctive flavor and color. Brown sugar is available in both light and dark varieties; dark brown sugar has the stronger flavor. You can substitute granulated sugar measure for measure for brown sugar, except in products where color and flavor might be important, such as a caramel sauce. In baked products that use baking powder or baking soda, add 1/4 teaspoon more baking soda for each cup of brown sugar used in place of granulated sugar.
Powdered sugar: Powdered sugar, also known as confectioner's sugar, is granulated sugar that has been milled to a fine powder, then mixed with cornstarch to prevent lumping. Sift powdered sugar before using and do not substitute it for granulated sugar.
Honey: Honey is made by bees from all sorts of flower nectars. It adds moisture, sweetness, and a characteristic flavor to baked goods. Because it caramelizes more quickly and at lower temperatures than sugar, honey causes baked goods to brown more quickly. It is also available in whipped forms.
Corn syrup: Corn syrup is a heavy syrup that has half the sweetness of sugar. It is available in light and dark varieties. Like dark brown sugar, dark corn syrup has the stronger flavor.
Granulated, or white, sugar: Granulated, or white, sugar is the most common sweetener used in baking. It is made from sugarcane or sugar beets. White sugar is most commonly available in what is called fine granulation, but it also comes in superfine (also called ultrafine or caster sugar), a finer grind of sugar that dissolves readily, making it ideal for frosting, meringues, and drinks. Pearl or coarse sugar is just that -- a coarser granulation best used for decorating cookies and other baked goods.