Finding good keywords for you website is one of the most important aspects of search engine optimization.
To obtain maximum search engine visibility, it is essential to understand how the target audience is searching for actual information on a web site. When the target audience uses a search engine to find products and services, they type a set of words or phrases into the search box. This set of words is commonly called targeted keywords or phrases. For the target audience to find a site on the search engines, the page must contain keyword phrases that match the phrases the target audience is typing into search queries. (http://en.wikipedia.org/wiki/Seo)
There are a number of tools available for finding good keywords for your website. However, you'll need to work out the keywords that you think are most relevant to your website. A list of 10 or so keywords is a good starting point.