Getting Different Size Of Attachment Images

Since you have defined the featured image for each post with using <?php the_post_thumbnail( ‘custombig’ ); // or another custom size name ?> should be enough, for info you can read: http://justintadlock.com/archives/2009/11/16/everything-you-need-to-know-about-wordpress-2-9s-post-image-feature http://markjaquith.wordpress.com/2009/12/23/new-in-wordpress-2-9-post-thumbnail-images/ Or here there is good info too: How wordpress handle upload images and how to use them in the code