pagination for custom select query

hey, im having a problem. Im not very good in php and need to add a pagination for this query (it shows upcoming events..).

<?php // Build a custom query to get posts from future dates.
					$querystr = "
   	 				SELECT wposts.*
    				FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
   	 				WHERE wposts.ID = wpostmeta.post_id
    				AND wpostmeta.meta_key = 'Date'
					AND STR_TO_DATE(wpostmeta.meta_value,'%m/%d/%Y') >= CURDATE()
					AND wposts.post_status = 'publish'
					AND wposts.post_type = 'post'
					ORDER BY STR_TO_DATE(wpostmeta.meta_value,'%m/%d/%Y') ASC
					LIMIT 20
					";
					$events = $wpdb->get_results($querystr, OBJECT);
					if ($events):
					global $post;
 					foreach ($events as $post):
 					setup_postdata($post); ?>
						<div class="post-thumb-title">
 							<a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php the_post_thumbnail(array(160,281));?>
 								<p class="thumb-date"><a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php echo get_post_meta($post->ID, 'Date', true); ?></p><br>
 								<p class="thumb-title"><a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php the_title(); ?></p>
							</a>
						</div>
				<?php endforeach;
				else : ?><li>Sorry, no events coming up.</li>
				<?php endif; ?>