Elements has some great tools for creating digital scrapbooking papers with a torn edge look. Open any digital paper and create a background layer with a complimentary color. Select the erasure tool round brush at about 50% opacity and erase away the part of the paper you want removed, creating a jagged line for the edge of the paper. For a solid background color, erase at 100%. The example below shows the paper on the top layer and solid orange on the background layer.
With the paper layer still selected, choose the burn tool and paint along the 'torn' paper on both sides of the jagged edge to add some depth.
Next, make white the foreground color, select the paint brush and paint along parts of the torn edge with a spatter brush to simulate the torn effect.
Experiment with different brush tips and settings to get a variety of torn edge and paper effects for your scrapbooking layouts.