I've finally managed to figure out Multiple Loops and get different Categories displaying with different formatting on the Index page.
Now what I would like to do is randomise the display of posts for one specific category. Currently the loops I'm using is:
<?php query_posts('category_name=releases&showposts=3'); ?>
<?php while (have_posts()) : the_post(); ?>
// write post according to formatting
<?php endwhile; ?>
I've downloaded the Random-Posts plugin but I've tried to no avail to get it to work with this loop.
The key thing is - they don't necessarily need to display randomly, just so long as they change slightly upon refresh.