The simplest breadcrumb for WordPress
There are of course lots of plugin for WordPress, especially breadcrumb. I normally like to minimalise my WordPress and use as less plugins as possible.
First, understand the overall WordPress template system.
<?php echo get_option('home'); ?>"> = Link to index.
<?php the_title('argument'); ?> = Title of the post and/or entry.
<?php the_category('argument'); ?> => Category.
Get it? So if breadcrumb looks like Apple site:

It should be simple as:
<ul>
<li><a href="<?php echo get_option('home'); ?>">Home</a></li>
<li><?php the_category(', '); ?></li>
<li><?php the_title(); ?></li>
</ul>

Place it on single.php will do
That is the for post, which has category. For pages, just delete the category tag:
<ul>
<li><a href="<?php echo get_option('home'); ?>">Home</a></li>
<li><?php the_title(); ?></li>
</ul>

Place it on page.php.
Of course you’ll have to style it according to your own design.