Charts showing the amount of sugar in foods are available on Found Health, The Fruit Pages and 360 Blog. These charts show the relative sugar content for specific food groups, such as fruits or energy bars.
The Fruit Pages offers a useful chart for determining the nutritional specifics of many different kinds of fruits. This chart lists the amount of sugar in a 100 gram serving of each fruit, as well as the amounts of fat, protein, fiber, and several different vitamins and minerals.
The chart on Found Health deals specifically with store-bought energy bars. This chart shows only the sugar content, in both grams and teaspoons per bar. The sugar content chart from 360 blog is focused on packaged cereals, specifically those that are made to appeal to children. The chart lists the grams of sugar in nine popular cereals, calculating the amount of sugar in different serving sizes.
Another site that shows the sugar content of foods is Sugar Stacks. Photographed charts made from stacks of sugar cubes give the viewer a tangible example of how much sugar is in many different foods, including vegetables, sauces and packaged snacks. The amount of sugar in grams is provided beside each image.