I definitely recommend you have a read of this book:-
"Don't send a CV" by Jeffrey J Fox
Although the title may seem a little off-putting it is excellent at helping you understand why companies hire people, what they're looking for and what they're not looking for.
I've read it and the advice is excellent, it's also very easy to read and quite cheap too...the best £7.99 you can spend.
Good luck and feel free to post your CV on here or email it if you want someone to proof read it.