Typically start with a master story. A master story is a fairly detailed chapter of what you see the solution doing. Include everything needed to give a full picture of the solution - do look at how you intend to solve it (unless there are novel ideas that should be mentioned), but do go into expectations from all parties (admins, users, system etc). Someone should be able to read it and have a very good idea of the overall picture of your concept. Although it may be more technical than anything outlined in a business plan, it should be targetted at an audience with knowledge of the domain and/or technology - at a high level at least.
AggregateIt will allow registered users to save a URL by right-clicking on any browser page and sending to a central database. The central database will store the URL with the users account and at regular intervals poll the site to check for RSS feed updates. Upon finding updates, the updates from all sites in some period will be aggregated and emailed to the user.
Note that we discuss some concept behind the solution, but leave the detail. There are other points around features such as registration, security and so on that could and should be discussed. Someone can read the master story and break it into many sections which can then discuss the detail - this means that all sections should be covered in some manner in the master story.
Next time we will look at creating sections and sub-stories.
