Exclude Categories From Your Home Page
Placing this code in your index.php file will cause your home page to display posts from all categories except category ID 3.
<?php
if (is_home()) {
query_posts(“cat=-3”);
}
?>
You can also add some more categories to the exclude-list(tested with WP 2.1.2):
<?php
if (is_home()) {
query_posts(“cat=-1,-2,-3”);
}
?>