Posting

You Make those categories and then link the categories in your menus. Then your Home page would be a static page instead of your blog.

You can just place a direct link to a specific category including the category id. The actual link depends on if you are using permalinks.
You can also include in your navigation to list ctaegories which I believe is:
<?php wp_list_categories(‘show_count=1&title_li=<h2>Categories</h2>’); ?>

Or you can use the tags. Depends on the result you are after. For instance a car club site might have categories for car shows, technical info, member pictures, etc. Have in the menu direct links to each cat. As long as members post to the correct category it will keep them organized. But if you want say certain car shows and pictures posts to sometimes show grouped together on the same page, then you use tags.
Hope that helps.