How to Exclude Category Posts

This one allow you to exclude a category on the home page blog, but still keep it in the sidebar.  Add the following to your functions.php file:

function exclude_category($query) {
if ( $query->is_home() ) {
$query->set(‘cat’, ‘-xx’);
}
return $query;
}
add_filter(‘pre_get_posts’, ‘exclude_category’);

See more info on this here: http://www.locoed.com/web-design/how-to-exclude-category-posts-wordpress-tutorial-code/