The AllSet Learning Grammar Wiki is a mini-Wikipedia devoted entirely to Chinese grammar. It has recently been made publicly available, and is organized according to the following principles:
Organized by Level. The Chinese Grammar Wiki was designed to be useful to learners of all levels, but with special consideration for the beginner. The Chinese Grammar Wiki organizes grammar points by level, and then also ties them all together with lots of links.
Organized by Book. AllSet Learning has built up a decent library of Chinese textbooks and grammar books. These are the books cited as references when editing the wiki. Where possible, they’ve also tried to link textbooks’ contents back into the Chinese Grammar Wiki content.
Always Referenced. Editors cite the resources they use, which can give learners some ideas for useful print resources.
The wiki is available at http://resources.allsetlearning.com/chinese/grammar