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

Recommended and introduced by Trevor [here](http://www.hackingchinese.com/extensive-listening-challenge-october-2014-wrapping-up/#comment-646686). Each book (one for each level of the new HSK ex... Read more.

amazon.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

Pinyinput is an input method editor (IME) for Windows that makes it easy to type Hanyu Pinyin with tone marks, like so: Hànyǔ Pīnyīn. Read more.

pinyinput.net

This is the best overview of spaced repetition research I have seen online or offline. It's thorough, well-argued and probably covers more than you were looking for. It's not specifically about Chi... Read more.

gwern.net

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 article discusses the language power struggle that most learners are very familiar with. "Given a conscious choice between a number of languages to use for interaction, speakers will naturally... Read more.

sinosplice.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