How do I create a sticky sidebar?

I did not really understand your question, but try this (using bootstrap v3):

<div class="clearfix">
<?php $a = 0; $classes = array('post-1','post-2','post-3');
 query_posts('category_name=Menucard'); ?>
    <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

    <div class="<?php echo $classes[$a]; ?> col-4 post move pull-left">
        <?php
            //echo post here
            the_content();
        ?>

    </div> <!-- close .post div -->

    <?php
        $a++; endwhile;
        endif;

    ?>
</div>