A good rule of thumb to follow if your primary goal is to reduce your level of body fat:
- 80% of the problem is how much and what you eat
- 10% of the problem is exercise
- 10% of the problem is sleep and stress reduction
So don't count on being able to "exercise your way to skinny" - for most people, that is almost impossible. If you're serious about making a real lifestyle change to something sustainable over the long team, you should read "The New Metabolic Effect Diet". It is a science-based approach that is easy to understand and easy to follow.
And yes, I have the abs to prove it :-)