The DITA OT user guide (authored by Dick Johnson and Anna van Raaphorst) is an excellent reference and has tons of useful information. It's one of the best references on the DITA OT. Sometimes, however, I feel that it's sheer size is a challenge for users, especially first-timers. We as a community need to help improve the existing DITA OT documentation by making it more user-friendly. Both Anna and Dick are busy and I have volunteered to reorganize the user guide and possibly break it down into smaller ones targeted by specific audience groups.