The zone record is added!
Ok Matthew, it sounds really hard, but it's not bad at all.
So whoever registered the site should have log-in information from that registrar (looks like Fasthosts). You will need to be able to log in to the registrar's site.
Once you log into your domain registrar, you will see options for your domain name, including updating the nameservers (you have specific nameservers, and they are NS1.WORDPRESS.COM, NS2.WORDPRESS.COM, and NS3.WORDPRESS.COM - you may only have space for two, in which case, just add the first two).
You'll want to save and exit. At that point, it can take a little while for the nameservers change to propagate (a few hours, usually).
Once you've done that, you will want to log in here at WordPress.com, and follow these instructions for mapping an existing domain:
Here's the gist:
Once your nameservers are properly updated (wait a few hours at least), go to your Dashboard > Store > Domains, and type your domain (porttalbottown.co.uk) into the box, and click "Add domain to blog" - once the nameservers are verified as correct, you'll be prompted to purchase the domain mapping ($13). Once you make that purchase, your domain will be mapped to your blog!
Please note that the mapping can take several hours to go into effect.
So I hope that helps - but start at the very beginning, and get your registrar log-in information in hand.