Remove post title

WordPress does not require entering post titles, at least not in the backend. You can leave that part of the form blank.

As far as your theme is concerned, that will depend on the theme author and whether they’ve considered someone not entering a title. The default twentyeleven theme handles it fine, linking to the post page using the date posted, but not all authors will be that thoughtful. If the theme you’re using doesn’t have an alternative, you could try editing the loop.

Depending on how the theme is set up, there might be only one loop, or several for different purposes. You’re looking for loops related to archives, categories, tags, searches, and the home page. Often there will be a “default” loop that just gets all those values (“loop.php”). Look for code with title tags and <? the_title(); ?> inside them. Most will look something like this:

<h2 class="entry-title">
    <a href="https://wordpress.stackexchange.com/questions/70721/<?php the_permalink(); ?>" ><?php the_title(); ?></a>
</h2>

All things considered, you can usually just leave this alone. When there’s not text to fill it out, the <h2> tag above just collapses and disappears. Trouble is, you need something else to link to the post page if this is the only link. The TwentyEleven theme provides just the thing. Add this function to your functions file:

function twentyeleven_posted_on() {
    printf( __( '<span class="sep">Posted on</span>
        <a href="https://wordpress.stackexchange.com/questions/70721/%1$s" title="%2$s" rel="bookmark"><time class="entry-date" 
        datetime="%3$s" pubdate>%4$s</time></a><span class="by-author"> 
        <span class="sep"> by </span> 
        <span class="author vcard">
        <a class="url fn n" href="%5$s" title="%6$s" rel="author">%7$s</a>
        </span></span>', 'twentyeleven' ),
    esc_url( get_permalink() ),
    esc_attr( get_the_time() ),
    esc_attr( get_the_date( 'c' ) ),
    esc_html( get_the_date() ),
    esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ),
    esc_attr( sprintf( __( 'View all posts by %s', 'twentyeleven' ), get_the_author() ) ),
    get_the_author()
    );
}

Then you can call it in the loop near where the header shows up:

<h2 class="entry-title">
    <a href="https://wordpress.stackexchange.com/questions/70721/<?php the_permalink(); ?>" ><?php the_title(); ?></a>
</h2>
<?php twentyeleven_posted_on() ?>

Hope this helps!