Google actually searches for PAGES NOT WEB SITES
It reads the content of these pages and gives them relevance to the search
Use google keyword tool to find keywords with over 2000 results, "Key phrases are better" then type these in google search, look at the top where it tells you how many results there are, if higher than 60000 try another key phrase, there is too much competition.
Above anything else on your site place a line of text with your keyword phrase, make it an H1 tag or heading 1 ( you can adjust the size of the font but make sure it is big and is bolded )
Directly below this insert another with line with a bit more text making sure you use these same words ( but not exactly the same phrase, ensure it is an H2 tag) again bold
Now give your page lots of content, use the phase a couple of times only and the main key words throughout
Get webmaster tools through you GMail account
Verify the site
Insert google bot file
Insert sitemao.xml file
Get google analytics and watch your site improve its rankings
All this is FREE
Did this with my site Promotion Productions, we have number one normally for the search "custom screen printed t shirts Auckland" I am in New Zealand so the small population is probably why.
In fact if anyone wants to do me a favour and type this in where you are, I'd be very interested to know how it ranks elsewhere, Ruby world cup coming up here so could get some overseas work, I have targeted it but no bites as yet.