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Site looks nice, Paul. If you haven't done this already, use the SeoMoz tool to check your onpage setup: http://pro.seomoz.org/tools/on-page-keyword-optimization/new Fix anything that needs work and then start promoting your site. You can set up tracking here: http://www.seomoz.org/rank-tracker You will be emailed regular updates, that show if you are making progress. As it is a real site, issue a press release every week, about something interesting you are doing or that is of interest to people buying travel insurance in Ireland. Change which pr site you use, so they aren't all from the same one. Write other articles and get them published in other places - offer them to your local news sites.

From what I've read, there's no hard answer on a percentage. I've heard recommendations to keep it around 5% to optimize but under 10% for stuffing purposes. Aside from using tools to analyze the content, you can usually tell a lot just from reading. If a page is stuffed with keywords, it's not too hard for a human to tell.