Blog Posts on Home Page by Category

Hi guys, just a quick query, I am using the Plixus theme on my website, and one of the features is on the Home Page it can display your last 4 blog posts. This is nice, however I am using Blog Posts in categories for other uses too. What I would like is a way of having the blog posts display by category only, I have the category already and the ID.

I’ve wittled it down to the following code:

<?php
       $blog_nr = of_get_option('blog_nr', '' ); 

$recent = new WP_Query("showposts=$blog_nr");

	$count2 = 0;

	 if (have_posts()) : 

	while($recent->have_posts()) : $recent->the_post();?> 

	<?php if(($count2 % 4) == 0) {  	?>

Does anyone have any ideas which part of this I’m changing in order to get it to display categories from either ID of 8 or the slug ‘blog-posts’.

Thanks for any help.