I don't know if it's pheromones, but there are glands in various places. But yes, there are other communication clues they use too, that are probably easier to read. But this is just one more you can use to help get to know your dog.

Humans have co-evolved with dogs for a very long time, some theories put it at over 100,000 years, and it may have been our advantage over the neanderthals. So we already have a pretty good instict for reading dog body language. But it's not all obvious, and I learned a lot from this book:

Dog Language: An Encyclopedia of Canine Behavior