Choosing a good whey protein is the most basic supplement you can take. I always recommend taking a multivitamin and fish oil supplement to everyone. Their benefits are huge. After these it all really depends on how much you want to spend. Nitric Oxide is an awesome pre-workout that will give you a ton of energy and focus during your workout. Weight gainers can be a good substitute whey protein if you are looking to put on large amounts of mass. Finally casein can be a good idea to take prior to bed to make sure your body is supplied with protein all night.