Agree with the others. The coding is solid and very impressive for a first attempt. I wouldn't go investing in Dreamweaver and end up having it write code for you because it'll end up being a mess. So that is £600 saved right off the bat by having the commitment to learn code and not 'drag and drop'.
One tiny point on the code is that your list tags in the menu should really be wrapped in an unordered list tag.
Code:
<div id="navigation">
<ul>
<li>Home</li>
<li><a href="tarrif.html">Tariff</a></li>
<li><a href="breakfast.html">Guests' pantry</a></li>
<li><a href="white.html">White room</a></li>
<li><a href="red.html">Red room</a></li>
<li><a href="green.html">Green suite</a></li>
<li><a href="location.html">Location</a></li>
</ul>
</div>
But that is easily sorted.
Also agree that the SEO could do with just some subtle changes. For example your h1 tag on the front page. It wouldn't hurt to change it to "Welcome to Tankerfield House Bed and Breakfast in St Albans". That just helps location searches and hits a key search term.
Other than that you are looking at perhaps doing some more interesting graphics or playing with the colour scheme a bit. GIMP is a free graphics editor that may help; GIMP - The GNU Image Manipulation Program
Hope some of that helps.