Delia on line obviously I had to begin with Delia - the best! Her site is full of everything you could possibly need to know about food. Your Christmas is all wrapped up for you here and the videos are mouth watering.
Jamie next - Jamieoliver.com - another brilliant site. I like his straight forward style; he makes everything seem simple but occasionally I have felt the finished dish lacked something ... not every time (who am I to criticise!).
BBCGoodFood site have some great recipes (but the adverts get on my nerves) and Simply Recipes is a good site if you are stuck for inspiration.