Sorry, to be clear, we have multiple chapters, all of them in separate geographical locations. This is shown in the pages such as Toronto. For each of the chapters they will want to be able to blog on the activities, events, and the outcomes of these as they are happening. As well I had hoped they would be able to post pictures with their blogs on their pages, centrally located under our main website.
I think this partly depends on how much control you would like to give each chapter. It sounds like you might actually want each one to have their own blog, such as toronto.oneparentfamilies.net* or some other name, so they can all blog as they go.
* Note that setting up a custom subdomain like that for each chapter would be a $12 per year per custom subdomain fee, so if you're tight on funds then you may want to look for other creative ways to make the same thing happen.
The way you have http://oneparentfamilies.net/ setup now, each chapter is a page and that is indeed pretty static. To start, check out this background info about posts vs. pages and post categories:
Based on what you said earlier, it sounds like pages are not a good fit for the chapters, so think about using categories for each chapter (check out the help page linked above) or possibly creating a separate blog for each chapter which are all linked together by the main oneparentfamilies.net blog.