Hello, guys.
I had some experience with Skype instructions as well, and |I must say that they work just fine. Make sure that you are alone in the room, that your connection is good and that you can hear the instructor fine. Turn off your phone and set your online status on "Invisible". Believe me, those small things can ruin the entire session.
If you are worried about your pronunciation, go and check out the software that helped me the most - http://saundz.com/. It teaches only pronunciation, so further instructions are necessary, but it worked just fine for me.