I'm a software developer at a technology company. I have been tasked with leading the documentation effort for the product I work on. The goal is to produce documentation internal to developer, and the project spills over into the business side, where it covers requirements documentation.

This project is challenging. Specifically, I'm dealing with a product which: - has been around for a long time, at least 6 years. - has no form of documentation other than some small, outdated pieces here and there. - has comments in the code, but they are technical and do not convey any over-arching behavior (even on technical side). - as a consequence of having little to no documentation, is often unnecessarily complex under the covers

In addition, we have not been given a lot of time to work on this project.

I do not have any formal documentation or writing background, training, or experience. I have displayed some ability in writing/communication around the office, which may be why I was assigned to this project.

Please share your advice or recommendation for resources to help me prepare and deal with this project. I'm looking for references to books/website/forums/whatever, to help me come up with the design of a plan with milestones, learn about best practices, task delegation, templates, buy-in, etc.

I'm hoping specifically for resources targeting or giving special mention of introducing good documentation to existing, undocumented, projects.

I would be very grateful for your responses.

Ben