Return posts page to show posts from all categories

I’ve played around the page that displays my posts. At the moment it only displays posts from a particular category, but I now want to change it to display posts for all categories, and have pagination.

Here’s my current code:

<?php  

            /* This is the new loop to display a featured story.
             * It creates a variable and then loads all the posts that match the query.
             */

$my_query = new WP_Query('category_name=Advice&showposts=10');
$do_not_duplicate = $post->ID;
            /* Now it loops through the results and displays the content.
             */

while ($my_query->have_posts()) : $my_query->the_post(); 

            /* Then it displays the title as a working link with formatting to
             * match the Twenty Ten template.
             * Then we display the excerpt.
             * Then we finish the loop with the endwhile statement
             */
?>

What do I need to change