Before starting please note, Pages do not have categories, but Posts do. I will mainly refer to Pages below. Also note my example assumes you are using the WordPress Default Theme and that you have 6 POSTS assigned to a category called Numbers. I'll assume Numbers is category ID 3.
Copy wp-content/themes/default/archive.php to wp-content/themes/default/onefront.php.
Edit onefront.php and change:
<?php
/**
* @package WordPress
* @subpackage Default_Theme
*/
get_header();
?>
to
<?php
/*
Template Name: OneFront
*/
?>
<?php get_header(); ?>
and change:
<?php while (have_posts()) : the_post(); ?>
to
<?php query_posts ($query_stingw . '&cat=3'); ?>
<?php while (have_posts()) : the_post(); ?>
Add a new Page called One. Add a new Page and called Blog. In Administration > Settings > Reading, set the Front page displays to A static page, and select One for Front page:, and select Blog for the Posts page.
Enjoy!
Related:
Stepping Into Template Tags
Stepping Into Templates
Template Hierarchy