Introducción: Pinyin y tonos

Introductory Lesson:
http://www.youtube.com/watch?v=zNoOdNvdZlg&playnext=1&list=PL3FE95829801212B9
Introduction of Pinyin and Mandarin Four Tones
http://www.youtube.com/watch?v=FIxK7mEYFBI&feature=player_embedded
First Tone and Second Tone
http://www.youtube.com/watch?v=IWsgTDoTtH8&feature=player_embedded
ü and its spelling rules
http://www.youtube.com/watch?v=AMNu5WEmOoI&feature=player_embedded