There are three types of nutritional supplements people take around workouts. Ones before, or pre, ones during, or peri, and ones after, or post. Each one has different nutritional components and serves its own purpose. The different supplement combinations you mix for these shakes are sometimes referred to as a 'stack'. You customize your stack by brand and supplement to suit your needs.
The pre-shake usually consists of branch chain amino acids. These will come in handy during your workout to help you not hit a wall and get the most out of your workout.
In the peri-shake, you usually have a carbohydrate/protein combo. The carbohydrate, or sugar, should be light. Watered down Gatorade is a great option, or the G2 Gatorade that is designed for during physical activity also works. The protein can be a whey protein that is easily broken down and absorbed. This shake will also aid in keeping your energy high for a maximum workout performance.
The post-shake should be a carbohydrate and fast digesting protein, like whey. You want to stay away from fatty protein options because fat will slow down the digestion and absorption of the nutrients. Keep protein options like milk for before bed or overnight as a slow release form. For the carbohydrate, options like juice or regular Powerade and Gatorade are good. Some nutritionists will argue that the simple sugars you ingest in the first 20 minutes after a medium-high intensity workout don't count toward your daily caloric intake because they are burnt right away and won't get stored as energy. If you are taking creatine, these would also go in your post workout supplements. The goal of your post workout shake is to repair and refuel your body. You want to give your exhausted muscles nutrients to help repair them and give your body nutrients to get your energy up for the next part of your day.
The proper nutritional supplements will enhance your results you work so hard for. Think of it as putting high performance fuel in your vehicle vs the standard fuel. You will get better performance, cleaner burning, and all around better results.
Please note that this is general information. For specific plans designed for you and your training and activities please consult a professional that will design a plan to meet your needs. Always consult your nutritionist, personal trainer, and/or doctor when changing your nutrition plan.