How to output data into an array

Please help, i’m a noob to php and wordpress and have been trying to get a slideshow working for days …

What i want to do *i think* is create an array form items in the lounge category then add the thmbnail, heading and permalink into a list item.

Below i can display all the thumbnails but i can’t overly the tex tor permalink.

I need to understand arrays really so i can construct the array at the start of the page and then populate the divs with pertinent content from the array ..

<div id="slider"> 

    	<?php $my_query = new WP_Query('cat=Lounge&showposts=25'); ?>
		<?php while ($my_query->have_posts()) : $my_query->the_post(); $do_not_duplicate = $post->ID; ?>
    	<?php set_post_thumbnail_size( 180, 120,false ); ?>

<ul>
<li><?php the_post_thumbnail(); ?>
                </li>
</ul>
				<?php endwhile; ?>
	</div>