Wordpress has a couple of rarely used functions that allow author information to be displayed for the current post and a list of all of the authors on the blog.
Adding a written by message to your posts is not difficult at all. Just use the the_author_posts_link() function inside the post loop.
<?php the_author_posts_link(); ?>
This function shouldn't be confused with the the_author_link() function that prints out the link in the author's profile.
The second way of printing out author information is by using the wp_list_authors() function. This can take a number of arguments, but the simplest use of it is as follows: