A website doesn't have to be some grandiose, 'all singing, all dancing' scheme of dozens of pages. Although there is an argument for an overall plan and structure as you might expect in a book or other publication, this may imply delay and a 'static' finished product (as in a book or even newspaper). This seems to undermine the essentially dynamic potential of the web. See Tim Berners-Lee, 'father' of the Web, on style in this connection.
Why not think of your website as part of the world wide library? Start with a contribution of a single page and add to it as time and opportunity allow. One problem with this approach is that growth can be haphazard, especially when a number of contributors - perhaps hundreds of staff, students or pupils - are involved.
The answer to this problem perhaps lies in that word 'growth'. Think of the website as a tree or garden. When it becomes tangled or overgrown, a little pruning or weeding is required. Each contributor can maintain their own 'plot'. Whilst this may weaken an attempt at an overall site 'identity', style or consistency, it may nonetheless be more productive.
A first page, - Graphics, - Navigation/Site-maps, - Education revisited, - MoreHTML, - Standards, - Garden Maintenance, - MoreRESOURCES