Ah OK this is a UK based website so you might not get the answers you're looking for
I would suggest, if you can afford to - do some unpaid work experience at a reputable magazine, to get your foot in the door. Even if that means carrying yourself on the back of another part-time job to pay the bills. Make contacts, get to know people in the business, and this will help you get to where you want to go. I don't know how many mags have a full time photographer on board, I had assumed most work on a freelance basis, so that might cause you problems. However, if you put yourself out there, contact some magazines and build your reputation, if only at first by offering some free work in exchange for exposure, then they will come back to you regularly if they like what they see.
I'm a graphic designer, I have done some freebies and gained invaluable contacts in the process who recommend me, it's where most of my paid freelance work comes from.