Thanks to swguy and styledata for the suggestions, and I will certainly follow them up. I had a quick look at Joomla! and the add-on Jomres. This could be good for another site that I am developing, that allows bookings to be made at multiple accommodations.

For Blue Wren Cottage, however, I am still keen to stick with what I have started www.cottagemaldon.com because I feel that it is "almost there". It is currently "live", and it has already made one booking.