I am assuming I can set up a posting facility on any more than the one "page".
That's not correct. There is only one dynamic page in a blog for posts and we cannot post to more than that one page. But we can create the appearance that we have posted to more than one page.
We organize our posts by assigning Categories to them. When we publish a post it automatically appears on the running page for posts and also on the Categories pages and Archives pages. Note: There must be one published post in each Category in order for there to be anything to display.
A custom menu allows you to display Categories with drop-downs to sub-categories in tabs along the horizontal navigation where normally only Pages tabs are displayed. If you wish you can also include Pages with drop-downs to sub-pages and/or custom links in your custom menu as well. You are in charge of what appears in a custom menu. You choose the order in which to display any and/or all the foregoing in your custom menu. You choose which to display and which to hide. http://en.support.wordpress.com/menus
Also note that if you do not want all the posts to show on the front page, then you can create a static front page for your site, and also create a “blog” page for your posts to display on, but that’s optional.
So, can I just check that I've got this right - once I start posting for real, the traffic flow should increase?
That will help but with search engine indexing but there's much more to do when it comes to blog promotion. This is not a case of build it and they will comes. This is a case of promote very post you publish to those who your believe are your target audience and on the social networking sites that they are situated.
See here please http://en.support.wordpress.com/getting-more-views-and-traffic/