I've been working on a restarted version of the "OpenJDK Developers' Guide" and I have a draft far enough along for general discussion. The content of the existing guide is primarily logistical and procedural in nature; in time, I plan to migrate this information to a JDK 7 specific page because many of the details are release-specific. The new guide is more conceptual and once completed is intended to be able to last for several releases without major updating.
The table of contents of draft version 0.775 is:
The full draft is available from here.
All level of feedback is welcome, from correcting typos, to stylistic suggestions, to proposals for new sections.
Significant feedback should be sent to the project alias for the guide.
Initially, I plan to maintain the guide as an HTML file and publish new versions as needed. Over time, guide maintenance may transition to more formal version control, such as a small Mercurial repository or a wiki.