The most basic thing you can do with a blog in WordPress is add a post. This is a very simple guide to adding a standard post.
Adding pages is much more simple but the same rules apply. You just don’t have categories, tags and excerpts to consider with pages.
This download goes through adding a title and text plus:
- Comments and track backs
- Adding an image
Also what to do if you cannot see all of the fields you need by using the screen options.