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

Learn Chinese Online with CLO - Go from absolute beginner to intermediate learner with our step by step, progressive audio lessons in Mandarin Chinese Read more.

ChineseLearnOnline.com

This is a basic video demonstration of the stroke order rules for writing Chinese characters. It's short and if you find something lacking, your question may have already been answered in the comme... Read more.

youtube.com

This site contains a huge number of lessons, complete with texts, vocabulary, audio, exercises and much more. And it's all free. Note that if you want to get the intermediate and advanced material,... Read more.

collections.uiowa.edu

Finally, Duolingo added a En->ZH course. As Duolingo is the most popular gamification learning app, the learning experience is relatively streamlined and tested. The monetarization aspect leads to ... Read more.

en.duolingo.com

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 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 website and podcast offer theme-based, progressive online audio lessons. There are transcripts, worksheets, mobile apps, videos and more. Not all of this content is free, but the beginning of ... Read more.

melnyks.com

HSK Course is an online platform for HSK preparation. It aims to help you not only successfully pass the exam, but gain confidence in using Chinese language. It mainly has 3 parts: Grammar Les... Read more.

hskcourse.com

This page offers several hundred lessons for Chinese about different topics, including both reading practice and listening. They also have some learning activities, including quizzes. I have tried ... Read more.

gloss.dliflc.edu

HiNative is a Q&A site where you can ask people all over the world about culture, language, anything. We support over 100 languages. Read more.

hinative.com

Mastering Chinese characters, whether you find them enchantingly beautiful or overwhelmingly complex, is essential for literacy in Chinese. Outlier Linguistics will help you understand how the Chin... Read more.

outlier-linguistics.com

A blog written and managed by an advanced Chinese featuring reviews of books, TV dramas and games. Additionally, the blog also features recommendations for utilising media in Chinese language learn... Read more.

thecozystudy.com

The Chinese Language Institute (CLI) offers free Mandarin learning resources in the form of articles on a variety of topics including Chinese characters, Chinese grammar and chengyu. They also offe... Read more.

studycli.org

This is a presentation by Thomas S. Mullaney about Chinese typewriters through history. In the digital age, typing in Chinese is easier than it has ever been, but how did the Chinese typewrite evol... Read more.

youtu.be

This list is somewhat unique in that it draws on materials for people who learn Chinese as a second language, i.e. textbooks, graded readers and so on (read more about the methodology [here](http:/... Read more.

mandarininstitute.org

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 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

From their website: Features: - a game-based and structured curriculum optimized for English-speaking beginners; - compartmentalized contents designed for studying in fragmented times; - an... Read more.

chinese-skill.com

From their website (if you have personal experience of their courses, please leave a comment): New Concept Mandarin specializes in teaching Mandarin Chinese (Putonghua) as a second language. Act... Read more.

newconceptmandarin.com

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