Good overview of all the parts and pieces that have relevance to the site planning process. Just one afterthought. In our “Web Development Cycle” planning documentation we include a section in which we determine what standards need to be met for a given site. For instance, at one extreme, if the many of the audience are likely to be visually impaired, then obviously very high accessibility standards will need to be in place. On the other hand, for a small, temporary site that is for a limited number of people, down and dirty might be ok (though I still think that getting used to working in compliance with good standards is a good habit).
Checklist: Determining Standards for New Site.doc
A sample document that we use is attached. Feel free to use and/or comment on it.