So back when dogs roamed in the wild, they didn't have the same kinds of problems with their ears that they do now; their ears stood straight up, the fur was less susceptible to matting and collecting debris, and they had their pack members to groom them as the need arose. Nowadays, they depend on us for that kind of grooming (don't worry, no licking on your part required). If you just threw up a little in your mouth when you read those previous lines, never fear: it doesn't have to be gross -- if you stay on top of it.
If you aren't already, try to get into the habit of cleaning your dog's ears with a special solution (we sell some in our salons) or with ear wipes (yep, we also got those) every week. Make sure to gently wipe all the twists and turns of the outer ear canal. (Just don't dig in there too deep-- like humans, dogs' inner ears are delicate. And you're not gonna find treasure, no matter how deep you go.)
The inside of your pup's ears should be clean and pale pink (or the color of his skin). If there's lots of black stuff in there, that's ear wax, and having a lot of it may mean your dog has microscopic ear mites. Be gentle and don't overdo it either -- you don't want to make it raw. If you notice the ears are already raw or are overrun with dark wax, hop on over to your vet pronto, as you may be looking at a fungus or infection. Same goes for that head-shaking and constant scratching: not good signs. Once your dog's ears are clean and healthy, though, weekly maintenance cleaning should be all you need.
Three more things we should mention: if your dog has a lot of allergies, these may manifest in her ears. If she's got really furry ears, you should keep them trimmed or plucked to cut down on the nastiness accumulating. And lastly, if your dog swims a lot, make sure his ears are well-dried afterward -- that'll help keep bacteria from growing. You can even use one part vinegar, one part rubbing alcohol and squeeze a few drops in there to dry them up, as long as there are no sores or wounds in there.
If you feel weird or uncomfortable with any of this, come by the salon and we'll show you what we're talking about. We're all ears, friends. (Sorry, couldn't resist.)