First, let's define what should be expected in our final application:
A blog displays posts. A post is described by a title, a small description (that acts as a summary), the post's content, a category, a publication date, and an author.
The blog's home page displays a paginated list of posts. If the user clicks on the title, he should be able to see the full version of the post.
By clicking on the post category, a similar list should appear, but only displaying the posts belonging to this category.
Posts and categories should only be created and edited by authenticated users in the administration interface.
The length of the post's small description should be limited to 200 characters and edited in the Markdown syntax.
The content should be edited with a WYSIWYG plugin.
The administrators should be able to moderate comments.
Each time someone writes a comment, an email should be sent to the post's author.
We want to be able to easily install a new blog on other websites.