How do I get posts from category using the slug?

I have my own theme and I'd like to display posts on my home page from a specific category.

So far I've achieved it like this:

<?php
    global $post;
    $args = array( 'numberposts' => 10, 'category' => 6 );
    $posts = get_posts( $args );
    foreach( $posts as $post ): setup_postdata($post); 
?>

    <divs with the_title() the_excerpt() etc ></div>

<?php 
    endforeach; 
?>

But what if I want to get the category by a its slug? Or is it possible to simply make a category selection box in from within the admin panel?