With the plethora of information that exists regarding nutrition and "nutrient timing", I feel inclined to share some knowledge...
ARE SUPPLEMENTS NECESSARY?
No.... well not unless you're deficient in something. So don't believe all the marketing tactics!
WHAT SHOULD I EAT/DRINK BEFORE A WORKOUT?
Depends on when the meal is consumed... If it less than an hour before "gym time", you should avoid fats and fiber (longer to digest). The perfect pre-gym snack should be a piece of fruit! Fruit are simple sugars and will allow for rapid carb utilization.
If it is 3 hours before the gym, then you should consume 3 grams of carbs per kilogram of body weight (ie: 150lbs = approx 75 x 3 or approx 200 grams of carbs) and 15-25 g of protein.
SHOULD I EAT DURING A WORKOUT?
Generally...no. If your training exceeds 1 hour, then you may find it beneficial to consume 30-60 g of carbs per hour to maintain glucose levels.
WHAT SHOULD I EAT/DRINK AFTER A WORKOUT?
This is critical.
1 g of carbohydrate per kg of body weight PLUS 15-25 g of protein (within one hour post exercise). Follow this with a meal 2-4 hours post-exercise. This is the best way to replenish glycogen stores.
Ditch the protein shake! Instead, opt for some low fat chocolate milk or greek yogurt! Milk-based protein (post exercise) has been shown to increase muscle strength. Dairy is high in the amino acid Leucine, which optimizes protein synthesis.
It's simple. Ditch the 3 P's - (pills, powders, and patches)
Just eat food.