This site by Jun Da contains a lot of very interesting resources for anyone who wants dig deeper into frequency lists. One set of data I haven't found anywhere else is a frequency list of syllables... Read more.

lingua.mtsu.edu

This article describes the basics of way to teach tones that is different from the traditional way mainly in that the third tone is no longer described as a falling-rising tone (since that is rarel... Read more.

sinosplice.com

A website on the etymology of Chinese characters, with a lot of images of their past forms from different periods. Read more.

chineseetymology.org

This is a course offered by Peking University and Coursera. It's free to use, but you need to register (you can preview it before you register, though). There are six units, each taking roughly one... Read more.

coursera.org

This is a basic but fairly comprehensive overview of the phonology of Standard Chinese (or Mandarin, as it might be better known as). This site covers consonants, vowels, syllables, tones, word str... Read more.

en.wikipedia.org

This newly launched site offers basic information about pronunciation, mostly things that should be in all beginner courses and textbooks but seldom are. Currently, the content is fairly limited, b... Read more.

resources.allsetlearning.com

This is a comprehensive introduction to the world of digital Chinese, including the following: Script Basics Activate Keyboards for Typing Browser Recommendations Web Developm... Read more.

sites.psu.edu

Duanmu San's "The Phonology of Standard Chinese" is by far the best introduction to Mandarin phonology that I'm aware of. It's mostly useful for people who like phonology or are already at an advan... Read more.

hackingchinese.com

This is a unique resource that shows how most common speech sounds are actually produced. Most other resources use animations and diagrams, but this is the frist I see which show actual MRI scans. ... Read more.

seeingspeech.ac.uk

This is a very in-depth article about how Pinyin is written, focusing mainly on the letters used, the typeface, arrangement on the page, and so on. It probably contains more about this topic than y... Read more.

thetype.com

ChineseMe is the most integrated Mandarin course, designed for motivated learners who have decided to become fluent. It is an interactive textbook that adapts itself to your interests. The course i... Read more.

chinese-me.com

This is a free e-book with a collection of articles about how to learn Chinese, to which I have contributed one chapter about listening ability. This is a good collection overall with contributions... Read more.

livethelanguage.cn

This is a character-by-character beginner course in Chinese, provided free of charge at the Open Languages Project. It teaches you to read (and listen to) Chinese by explaining and introducing one ... Read more.

oplang.org

This site offers basics, self-paced lessons where you can learn basic vocabulary and grammar (usually with audio as well). There are also Skype lessons and other more interactive parts of the site ... Read more.

culturealley.com