You can tidy up the dashboard very easily by adding the following code between the php tags in your functions.php file:

// disable default dashboard widgets
function disable_default_dashboard_widgets() {
remove_meta_box('dashboard_right_now', 'dashboard', 'core');
remove_meta_box('dashboard_recent_comments', 'dashboard', 'core');
remove_meta_box('dashboard_incoming_links', 'dashboard', 'core');
remove_meta_box('dashboard_plugins', 'dashboard', 'core');
remove_meta_box('dashboard_quick_press', 'dashboard', 'core');
remove_meta_box('dashboard_recent_drafts', 'dashboard', 'core');
remove_meta_box('dashboard_primary', 'dashboard', 'core');
remove_meta_box('dashboard_secondary', 'dashboard', 'core');
}
add_action('admin_menu', 'disable_default_dashboard_widgets');

Obviously you can choose to delete a line for any widget that you’d like to keep.