If you've got a general practitioner or family doctor, they'll probably be willing to help you with your diet planning. After all, it's unlikely anyone knows all your vital statistics better than they, so they'll be able to suggest a particular diet, and may even be willing to provide you with the particulars.
Set realistic weight loss goals during your diet planning. There's nothing more depressing than not being able to meet your dieting goals, and if you're depressed, you're more likely to abandon your diet well before you actually get any noticeable benefit from it.