Carbohydrates have been given a bad rep in the past decade or so. Many people were probably depending on them far too much, structuring every meal around something which contains wheat (breads and pastas for example). When we choose foods that are higher in calories but don't offer as much nutritional density, yes, they lead to fat storage.However, fruits and vegetables are carbohydrates as well. As are legumes. And brown rice and other whole grains provide us with a ton of fiber, vitamins and minerals.
Carbs are the primary source of fuel for the brain. A good starch can tame hunger almost immediately, provide immediate energy for a workout, restore energy lost after a workout and generally brighten our moods. The trick is to not rely on them exclusively, and definitely learn the difference between refined carbohydrates and complex carbohydrates. Complex carbohydrates basically provide more nutritional bang for your buck. Because they are fully loaded, they take your body longer to break down. This contributes to your insulin levels remaining more stable, resulting in a steady flow of energy and an efficient metabolism. Refined carbohydrates, on the other hand, spike your insulin levels, resulting in unstable blood sugar levels, energy peaks and dives and encouraged fat storage.
When you eat carbs, be sure to eat them with some protein and some fat. This provides a well-rounded meal that keeps you fuller for longer, keeps cravings at bay (because your body doesn't bother you for more when it is provided with everything it needs), stabilizes blood sugar levels, maximizes workout efforts, makes you HAPPY, etc.
In terms of choosing the healthiest carbs, the best method is to choose foods which are the most natural and grow from the ground. Fruits and vegetables are obviously the most nutrient-packed, but we really need a strong balance. Legumes often provide some protein as well as fiber. Whole grains (millet, brown rice, bulgar, oatmeal, whole wheat breads / pastas, buckwheat) also offer tremendous nutritional benefits. The only reason why carbs have been linked with fat gain is portion sizes. When our meals are out of balance, it can mess with our blood sugar and thereby with our hunger, which encourages overeating! One serving of whole grains is one slice of bread, 1/2 cup of rice, 1/2 cup of pasta, 1/3 of a bagel... It is safe to sometimes consume up to two grain servings per major meal, depending on the individual and their goals.
Seek out a trainer with nutritional knowledge, or a registered dietician if you would like to know your personal carbohydrate requirements. Everyone is different - our needs all vary. But in general, carbs are amazing. Don't hate.