Dogs are very loving animals, of all the pets they have been labelled "man's best friend" because they are loyal and affectionate. Dogs make it fairly obvious when they love you but there are also some common signs of affection they display:
Like with humans, when you love someone, they are the person you want to be around. This behaviour is typical of dogs. Dogs follow you around in order to stay with you and be by your side. It can also be seen as a sign of protection by staying with you.
When puppies want to be fed they lick their mothers. When they are older they will lick other dogs as a sign of respect. This acknowledges the status of an older dog within their pack. Dogs can also lick you when they are anxious or stressed, but the most likely case is in a relaxed form when they are just licking you as a sign or affection and respect.