Wow, that's a big topic to cover! Dedicated SEO companies charge a fortune to do everything you're asking and chances are they wouldn't get the results you're after, at least not with any consistency. Don't know about a specific Google site optimisation application, but definitely sign up for Google Analytics and Webmaster Tools and read around the subject.

From what I've read the three main factors are: site longevity (Google favours sites that have been around for longer, not much you can do about that except wait); rich, relevant content and quality incoming links. The days of stuffing in loads of keywords in an attempt to trick Google are long gone, it's algorithms are far too developed for that now. Any quick fixes are likely to be counterproductive as Google with be onto you and penalize your site ranking.

These are a few tips I've read:
Keywords in URL, site title and headings.
Any keywords in text should read naturally; apparently Google pays more attention to the top and bottom quarter of each page (but no idea where I read that and if it still applies).
Putting keywords in bold and italic HTML tags could help, your CSS style sheets will override  this so they won't show on the page.
Keywords in file names of images, and their alternative tags (alt tags)
Obviously keyword rich meta tags for each site page individually (and having an XML site map is a good idea)
Incoming links from sites with high rankings should be built up over time and avoid too many outgoing links on your index page which will make your site look spammy.
Internal links, i.e. between pages of your site, not just in the navigational menu, may help your SEO, sure I read that somewhere .

It all takes time and consistent work so for now advertising in directories is probably the best bet, often I've found the best ones are free. What with the advent of HTML5 and the trend leaning towards mobile internet access (via smartphones) the time needed to get on the first page of Google may be better spent exploring more future proof alternatives anyway.

I'm beginning to wonder if choosing Dexi as my work name was a good idea.  I have more trouble trying to find my own website if I type in Dexi, dexi delite or dexi escort, than I do if I just type in Manchester independent escort or a variation of those words. 
My reasoning for a thorough search is because of a recent thread on another forum ( I do keep a check on my site regularly through Google Analytics, but not as thorough as this). Guys were trying to search for me and most said the only links they could find were on other escort directories and not my own site, and even then they really had to search for those directories.
I know people in general don't spend a lot of time trying to find a particular website if it doesn't come up on the first 3 pages of Google, but my hubby isn't a computer genius and I'm at a loss as to why my site is so low down the list.  Even my blog gets a higher rating than my site.   I don't want to have to pay for someone to make sure I'm on the first page when searching for girls in my area as most are scams anyway, or if they are genuine are asking a hell of a lot of money.
I seem to be doing everything that CeCe and Paris have mentioned in their posts as well as updating my blog and site regularly and still keeping a presence on forums such as Punternet, but does anyone have any other idea's that might help boost my Google ratings?  As I really don't want to have to change my name and start all over again.

Many Thanks
xx

Well, looking for 'dexi escort' here has you as #1, albeit the blog. The basic secret to SEO is 'content, content, content', which is why your blog has a higher rating than your site - there's more there. Console yourself that if they can find your blog, they can find you.

One advantage of using WordPress (the software) to run a website is that it makes it trivial to have a blog on it, rather than using blogger, blogspot or anywhere else.

Thanks Paris and Ian for putting my mind at ease.  I'll have a look into extra domain names and Wordpress.  xxx