SparkPeople is a FREE online diet website. You input your goals and such and it gives you ranges to stay within calories, fat, carbs, protein, etc... It will give you menus or you can make your own. A lot of people use this site in conjunction with other diets as well. I like to input my menus there to see my calorie intake and such. There are many message boards there as well. My "got my fingers crossed, hopefully one day" daughter-in-law has had much success with SparkPeople. They have a great phone app as well.
Live Strong is a diet website that one of my Spacey pals has been quite successful with. I remember she and I having breakfast last January in NY and we both ate exactly the same thing! I counted points, she was counting calories. Like SparkPeople you input some data to get your personalized calorie intake. They also have a phone app. There is a wealth of information available at this site - whether you do the diet or not, take a look at the site.
T.O.P.S. is another meeting oriented diet using the Government "My Plate" (it use to be a pyramid, now it's a plate). There's group support and a wealth of information. Check their site for locations near you!