Caleb is one handsome pup and I'm sorry to hear that his ear has been bothering him so much! The redness in and around his ear are most suspicious for a bacterial and/or yeast ear infection. Ear infections typically occur as a result of underlying allergies, and are quite itchy, resulting in intense scratching and head shaking. You can try to clean Caleb's ear with a balanced ear cleanser (
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=24165 ), but the only way to determine a) if he has an infection, b) the type of infection, and c) the best medication for treatment is to take him to the vet. There are no effective over the counter medications available to treat ear infections, as all are prescription based. If Caleb is obsessively scratching, you can put an e-collar (cone) on him until you can get to the vet to prevent him from causing more trauma to the skin around his ear. I hope that he's feeling better soon!