Other then on-page SEO (I'll come to that in a bit) do not neglect off-page SEO, firstly sign up for a google webmaster tools account, this makes a very big difference, and together with that you have your google analytics account. Make sure that you have a sitemap (xara does this automatically when you enter the websites domain name in the 'Publish' properties.

Secondly, once your site is online start creating the backlinks; forums are very good for this (this forum especially), though beware that a lot of forums now have 'NoFollow' links so for backlinks they are no good, but the more people who go to your website the better so they have their uses. Plus if you can get some backlinks from academic institutions or government ones then you are flying because google gives them far more weight.

Now we get to the most important aspect of SEO; on-page.

Firstly decide which keyword you want to target, remember one keyword per page, and do not use it more than 5 or 6 times on the page as it will be seen as spamming by the search engines. As I suggested earlier - use the keyword in the page title and make sure that the same keyword appears exactly as it does on the page title. If you want to check the popularity of a keyword you can use googles keyword advertising tools which show how popular a certain keyword or key phrase is, no point being number one for a keyword if no one actually searches for it.

Next; CONTENT!, make sure that it is original, that it makes sense to a human reader and do not repeat it on the other pages of your site if you can. Remember that CONTENT IS KING.

Also don't neglect Yahoo, sign up for an account and submit your site to that and to Bing as well.

Once your site is done then test it, speed makes a big difference so test it on http://tools.pingdom.com/fpt/ it will tell you how fast the site is loading and if there are any problems with large sized images etc.

Other than that there are plenty of resources on the web - but remember one thing, some people will say that a certain technique (in terms of SEO) works and that some techniques are no longer applicable but what I have suggested above WORK, I have over 100 websites I have done SEO for to prove that fact.

But do not neglect the look of the site, once the seo gets someone to your site, you want to keep them there and present a professional image which gets them contacting you, to be honest (my apologies but you need to know this); at the moment I would not be contacting the company to fix my roof, going by the look of the site I would think that either the company had closed down 7 or 8 years ago or would not trust them to do a good job, it's like giving a hand written quote or a business card which looks like it was printed off a machine at a train station.