I've never had to diet before but knew enough to know that killing yourself on the Atkins diet, or starving yourself on the Cabbage soup diet were daft so I bought the "You Are What You Eat Cookbook" by Gillian McKeith and changed what I ate.
I also stumbled across Don Lemmon on the Internet and found his mix of eating right and exercise more my thing. So I ordered his Book 1 (available from his web site below - stick with the page as there's a lot of info and if you read it all it does make sense). It's a really interesting read and teaches you a whole lot more about food - He basically splits food into 12 groups and teaches you how to combine certain foods and eat others separately. It's more of a life-style change and unlike other fad-diets you don't stop eating carbohydraytes or live on salad, but eat good food, more often. And to top it all he's a real nice guy who answers your emails and encourages discussion at his board http://www.liesandpropaganda.com/phpBB2/viewtopic.php?t=2
And what's great is Gillian McKeith agrees with some of what he says so you're never stuck for a recipe - I've learnt some great new dishes and now do all our cooking rather than just most of it :)
Anyway, the long and short of it is that I lost a stone and a half, dropped a couple of inches off my waist, got fit and look better than I did when I was 21 (I can even see my abs - at 36!). And I'm never hungry because the Know-How diet encourages you to eat.
It's great and it works. What are you waiting for?