For example, when first you enter the main weblog page, you're at the "top" category. Because the top category contains all other categories, it shows entries from all the others. If you click on one of the categories, say Creations, in the category outline, you'll see entries only from Creations and its subcategories: Art, and Photos.
Each weblog entry displays the category under which it is filed. The category is displayed as a link, so you can navigate directly to the category and see the other entries it contains.
A category only shows a certain number of blog entries (it's up to me how many). Eventually, I'll get around to archiving entries so that they're still available even after they've "fallen off" the bottom of the list.
Eventually, I'll incorporate this feature into an archive page or sidebar entry.
Of course, you don't have to type in the URL. There is an "RSS" link next to "Top" in the category tree, which subscribes you to the entire blog. When you're looking at a given category, the "RSS" link you see near the "breadcrumbs" (at the top left of the page -- it tells you what category you're browsing) syndicates just that category. For example, if you only want to get feeds for new Motorcycling-oriented blog entries, browse to the Motorcycling category, then hit the "RSS" link near the breadcrumb. If you're looking at an individual article, then clicking the RSS link subscribes you to the category for that article.
You can get a feed even for a date filter, but that wouldn't make much sense if the date was in the past, because the feed would never change.