Deliaonline.co.uk is pretty good. If you're really wanting to get cracking though, I recommend you buy a cook book, infact, Delia's 'How to cook' is good as she takes you from the very basics right up to advanced stuff.
Delicious magazine have their own web site. All the recipes that are in the magazine every month are also posted on their site....don't know why I subscribe really !!? Very good mag though - very good web site!