Well, usually with a lefty the drums are set up opposite from a right handed kit, with the hi-hat on the right of the bass drum. Then the sticking is inverted where R becomes L and so on. In my experience, being left handed can be a total advantage. I'm right handed, but one of my instructors was left handed and he played a open handed style. Meaning he did not cross his arms when he played the hi-hat and he played the bass drum with his right foot not his left. He was left handed and built up his right hand and became completely ambidextrous on the drums. He would switch the sticking in patterns, leading with the left or the right hand. If you check out some videos from Simon Phillips and Carter Beauford they play open handed all the time. It also seems that left handed players "take" to open handed playing better that right handed players. So that can be a total advantage, so you might want to talk to his instructor or maybe find a drum teacher in you area that teaches that style. If you google "open handed drumming" or check out
Open handed drumming from wikipedia you'll understand what I mean.
Good luck....