I’d recommend reading at least this guy’s blog and some of the articles on his site, starting with this: http://www.optimumnutrition4sport.com/?p=339
It’s a massive area to just start reading into though. If you’re after general advice, this: “kebabs, pizzas, chips, big portions of all” is not ideal! I think the main changes I made to my diet have been swapping white carbs for Low GI carbs (sweet potato, whole grain pasta, brown rice etc) EXCEPT immediately after exercise, oatmeal or muesli instead of breakfast cereal, whole milk instead of semi skimmed, butter instead of spreads, and much more protein!
Here’s his reading list too: http://www.optimumnutrition4sport.com/?page_id=368 I won’t claim to have read everything on there, but most of my nutrition is based around this guy’s advice. He works with steve cummings and many other pro cyclists and knows his stuff.