Some of the weightwatchers cookbooks are great, you can pick them up on ebay and I use the recipes whether i am dieting or not.
Basically with weightwatchers you drastically reduse your saturated fat intake.
Look at the nutritional values on the label of what you want to eat, if the saturated fat is less than 1g per 100g that can be considered low fat.
So eat fruit and veg and items low in saturated fat and you'll be on the right track.
(there is alot more to it than that, but thats the basic principle)