In the HTML pages of your site homepage find the following code, near the top of the page and fill in the keywords/description between the speech marks. keywords = what you think people will put in to a search engine when looking for a service like yours. I would go with window cleaning west riding, window cleaning, window cleaner etc. Seperate each keyword or phrase with a comma and a space
i.e window, cleaning, window cleaning,
Like this
<meta name="keywords" content="FILL IN YOUR KEYWORDS HERE" />
<meta name="description" content="FILL IN A DESCRIPTION OF YOUR SITE AND INCLUDE A COUPLE OF KEYWORDS" />
The text within your homepage should mention 'window cleaners [area]) a couple of times. (no more than 10% of the total text on the page)
Where you have got 'Gleem Clean' at the top on the picture, that is a Heading tag. Change that to 'window cleaners [area]' and put Gleem clean somewhere else.
Get yourself a map listing on Google Places.
There are a lot of free tools here
http://www.webmaster-toolkit.com/