If you're doing any form of exercise (particularly weights) whilst trying to lose weight (and believe me this is the best way to go about it) then you need to ignore any website that doesn't mention protein/carb intake and instead focus on websites dedicated to training and fitness.

The first thing to do is to work out your calorific requirements. I'll use me as an example.

I need around 3,200 calories per day to stay at the weight I am now. Because I want to lose weight I subtract 500 from this leaving 2,700. This means I'll be burning around 3,500 calories per week (in actual fact I think I burn more than this because last week I lost 2lb which is around an 8,000 calorie deficit)

In order to know how much fat, protein and carbs that you can consume you need to know how many calories they contain:

Fat: 9kcal/gram
Protein: 4kcal/gram
Carbs: 4kcal/gram

I then break down my carbs/protein/fats ratio into 55/30/15.

2700 * 0.55 = 1485 kcal Carbs / 4 = 370g Carbs
2700 * 0.3 = 810 kcal Protein / 4 = 202g Protein
2700 * 0.15 = 405 kcal Fat / 9 = 45g Fat

I then aim to eat these amounts, on average, per day.

If you're weight training and you want to build muscle and lose fat, when you start out, you can totally do this. The fat drops off you and the muscle flies on. Provided that your diet is right and you train right!

Like I said, 2 days a week weights with 1 day cardio should be an ideal formula to lose weight. And when I say Cardio, don't whatever you do sit on a treadmill for hours. There are a ton of cool and interesting workouts that will nicely supplement your weight training regime and get you out of breath at the same time.

Google:

Barbell Complexes
Kettlebells
Body Weight circuits
Plyometrics
Tornado Ball

Do 40 minutes of these and then 20 minutes on a treadmill/rower/ellipctal.

Lastly, it's worth getting a couple of sessions from a good personal trainer. A good one will show you some exercises and push you at the same time.