including WordPress posts into static website 
To make a "news" part of a static website more maintainable (and editable by end-user), I decided to include WordPress posts into that site. Doing so, I stumbled over issues with the post paged navigation.
Despite that, WordPress documentation about
The Loop in Action tells you everything you need to know to get your posts into your static website.
Just make sure to start your php file with
<?php include ('./blog/wp-blog-header.php'); ?>The trouble with the post-navigation was caused by the fact, that I installed WordPress into a subdirectory, while the posts actually would be shown on a page at the top-level directory. Now using the function
<?php posts_nav_link() ?>
would result in broken links as they would try to locate the current page url within the subdirectory.
Instead of checking out the original functions's php code I used hints from multiple sources and built up my self-made navigation. I haven't used php before, so there might be easier and much more smart ways to do this.
Nevertheless here is it in case you stumble across the same issue:
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>
<?php the_content('Read the rest of this entry »'); ?>
<?php endwhile; ?>
<?php
global $wp_query;
/* set paged if not set (entry page) */
if ($paged == 0) {
$paged = 1;
}
/*add newer link to entry page without $paged parameter */
if ($paged == 2) {
echo "<a href=\"";
echo $_SERVER['SCRIPT_NAME'];
echo "\">« newer posts</a>";
}
/*add newer link*/
if ($paged > 2) {
echo "<a href=\"";
echo $_SERVER['SCRIPT_NAME'];
echo "?paged=";
echo ($paged-1);
echo "\">« newer posts</a>";
}
/*add older link*/
if ($paged < $wp_query->max_num_pages) {
/*add new-old separator if needed*/
if ($paged > 1) {
echo " · ";
}
echo "<a href=\"";
echo $_SERVER['SCRIPT_NAME'];
echo "?paged=";
echo ($paged+1);
echo "\">older posts »</a>";
}
?>
<?php else: ?>
<p><?php _e('no entries found.'); ?></p>
<?php endif; ?>