I work for an organization that runs one of the most successful (and expensive) weight loss programs in the country, and even that program has plenty of flaws. Like others have said, the most important thing is not to be dogmatic and keep adjusting based on what works best for you.
Beyond that that, here are some things you should know:
-Sustainability is king. It's far better to lose 2-4 pounds a month sustainably than 2-4 pounds a week unsustainably.
-There's a million different diets, most of which are terribly off base, but some things are virtually universal between them. Processed foods, sugar, soda, junk food, fast food and so on are things everyone knows they need to stay away from. Start there.
-Be careful about vegetarian/vegan stuff, especially with your wife who's nursing. Here's a good resource that dissects a lot of that literature.http://rawfoodsos.com/the-china-study/
-Think about health, not weight loss. If you eat healthy, the rest will come.
And that's about it. I guess personally I'm a little biased towards paleo-type stuff (more the whole food + food quality aspect of it than anything else). I eat similarly to that and maintain around 8% body fat (based on DXA scan) and my clients have had a lot of success eating similarly.
Cheers and good luck!