Repair Clinic and Appliance-Repair-It.com both offer dryer belt installation tips and diagrams. Repair Clinic provides a larger variety of diagrams, while Appliance-Repair-It.com offers detailed installation instructions and diagrams for three major brands, GE, Maytag and Whirlpool.
Repair Clinic gives a list of brands and models and their corresponding dryer belt diagrams. The diagrams provide the style of the dryer belt mechanism and basic installation tips. Appliance-Repair-It.com gives detailed diagrams with labels for each part of the mechanism for GE, Whirlpool and Maytag dryers. This site also provides step-by-step instructions on how to install a new dryer belt for these three brands.