Current Post in full then Excerpts

That’s not too tough with a small modification to The_Loop but the trick is making sure that you don’t do it to subsequent pages (like when folks navigate to older posts).

In your theme’s index.php find
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
and add this right before that line:
<?php $postcount = 0; ?>
and add this right after that line:
<?php $postcount++;

Scroll down a bit to where your theme calls the_content() and replace that with something like this (keep in mind you might want to save your theme’s original the_content() line and replace it below):

<?php if ($postcount == 1 && !is_paged()) : ?>
   <?php the_content(__('Read more'));?><div style="clear:both;"></div>
<?php else : ?>
   <?php the_excerpt(); ?>
<?php endif; ?>

And there you go.