Introduction - Welcome to the Japanese Wikibook 
Development of this Wikibook began in August 11, 2003. It is an ongoing project that will evolve as users contribute to the content and layout of pages. The end goal of this project is to create an online resource for those wishing to learn Japanese. We will attempt to encompass all aspects of the Japanese language, including pronunciation, reading, writing, and grammar.
Many textbooks and travel guides make use of 'rōmaji' (Romanisation of Japanese characters) to bypass the need for learning the Japanese characters. This Wikibook, however, aims to develop a well rounded student, and as such, will make minimal use of 'rōmaji' except in introducing pronunciation.
Current work 
In the first five years, this Wikibook went through several rewrites. Seeing all too few contributors keen on picking up the torch where past editors left off, the book had amassed several layers of rewritten material that did little to provide a clear path through the material. Waking to that reality after considerable discussion, we came up with the categorisation scheme now present on the main page. The Japanese/Contents page does not conform with that scheme as it is more an inventory for editors looking for existing material to work with (be it merging, re-factoring, deleting, or rewriting), rather than an index for learners.
Since June 2008, a good deal of merges and rewrites have been done. As a result we've managed to delete over a hundred pages of unnecessary or duplicate material, navbars, printable versions, and templates. See Removal Suggestions for deletion proposals and discussions. For pages to be merged, see the Books to be merged category for a list of pages in this book that have been suggested be merged and Category:Japanese todo for pages with specific work to be done.
There hasn't been much discussion lately on the actual content since active editors (currently Retropunk and Swift) have been working on somewhat separate aspects of this book. We have a section on pages on structure, lesson plans and syllabus. How much to teach and Levels might also be of interest for those so inclined. For development of a consistent curriculum see User:Retropunk/Japanese Curriculum and Sugu ni Hajimemashō.
Finally; every contributor seems to have a different take on the purpose of this book. In your work, remember that learners have vastly different learning styles and diverse approaches to lesson plans will benefit readers and contributors alike. Until we have fully functioning learning paths, the categorisation scheme on the front page will make the existing material accessible to readers while allowing users to contribute without having to conform to a predefined form.
That said; pick your path and be bold.