Date of Birth is generally considered a requirement for CVs in the UK - its one of the first things I look for, it puts the whole CV into perspective.
Although he didnt say where he was applying for a job, given that his location is Preston, lancashire, England its fair to assume he's applying for jobs in the UK
In the Uk it is customary for your CV to be
Name & Contact Details
Relevant Skills (if applicable)
the order of education and work experience can be switched around depending whether you're a recent graduate or an experienced professional - the general rule of thumb is order the sections by importance.
Overall, its not bad, I would put your portfolio just below your skills though, its one of the most important and relevant things for a web developer.
Ditch the paragraph about your HND, all they need to know is that you've got one, they'll ask the rest at an interview.
Try to be concise (but use proper english), dont write more than 2 paragraphs about each job, get rid of the 'office worker' line, you have more relevant work experience than that and the dates overlap with your education so you dont need to account for that time.
Use bold rather than underline and dont justify your text, makes it harder to read. I know those sound like silly little things but it makes a big difference when you've got lots of CVs to read.
If you're going to leave references blank, dont include it at all. Most people dont these days, it something to worry about when you're offered the job
Keep your skills precise and to the point
PHP - 3 years experience
Oracle - studied as part of my HND
I would probably suggest that at your age and considering your level of education that your work experience should be before education. Also some of your specific skills should be listed in general - eg. Good Problem Solving Skills.
Most importantly, dont write too much, when I'm reading cvs I've usually got my boss talking in one ear about some insane marketing stunt and a collegue talking in the other ear about some coding problem, so I'm really just looking for keywords that jump out at me to give it a yes or a no and usually only read the thing properly while I'm walking down to the interview room.