1) http://www.learnchineseez.com/lessons/mandarin/pinyin/
2) http://www.freechineselessons.com/lessons/
3) http://www.chinaeducenter.com/en/learnchinese/lessons.php
4) http://www.cctv.com/program/learnchinese/easy/index.shtml
5) http://www.openculture.com/free_mandarin_chinese_lessons
6) http://www.minmm.com/minc/classes.php
7) ttp://www.clearchinese.com/learn-chinese/
8) http://www.uni.edu/becker/chinese2.html
9) http://www.digitaldialects.com/Chinese.htm
10) http://www.chinese-tools.com/