Then you're in trouble. Any serious athlete, bodybuilder, trainer, nutritionist, etc. you ask will tell you anywhere from 70% - 80% of your success will come from your diet. Period. End of story. While there are supplements that can help your efficiency on your way to your goals, nothing will replace a proper diet. Your body can't build muscle, which is made of nothing more than protein/amino acids, if your diet is lacking sufficient protein throughout the day. Your body can't adequately burn pre-existing fat while you keep dumping more fat and unnecessary carbs into it to replenish what's being burned off.
BTW, regardless of what supplement ads and labels tell you, "build 'lean mass'" is an oxymoron. Putting something to burn fat and something that helps build muscle into one supplement to do both at the same time SOUNDS like it makes sense, but biologically, it doesn't. Anything that burns fat will have an impact on your muscle building results. Anything that promises to pack on muscle will have an impact on your fat burning results. Not to mention you're talking about 2 totally contradicting workout regimens, contradicting diets, etc. for each goal. When you're trying to gain true muscle mass (not just weight), which is VERY hard to do, you have to eat like crazy, including a pretty hefty dose of complex carbs throughout the day. This excessive amount of calories, especially from carbs, is not conducive to burning body fat. On the other hand, while you don't have to go nutty with carb counting, you generally want to go lower when you're trying to lean out. Likewise, if you want to gain mass, cardio is your enemy, as it's taking away valuable calories your muscles need to grow, while leaning out requires lots of cardio to burn fat.
Point is doing both at the same time to their full potential is not realistic. Sure, you'll loose some weight while putting on muscle when you first get started just from your body not being used to what you're doing, but once that initial phase is over, it becomes virtually impossible to do both simultaneously. This is why competitive bodybuilders go through what's called an "off season", which refers to the non-competition/show period. During this time, they eat like crazy to try to pack on as much muscle as they can, knowing full well some excess fat and water weight is going to come along with it. Then 3 or 4 months out from show time, they start changing their workout and diet routines to lean out knowing full well they're going to LOOSE muscle during this time due to the lower carb/calorie intake and increased cardio. It is a necessary evil in order to make the results of all their hard work visible.
The only thing I'd recommend supplement wise if you're going to get serious with your workout routines is a good (at LEAST a 2-a-day) multi vitamin, a good fish oil and some plain old whey protein with maybe a bottle of extra l-glutamine (60% of what your muscle tissue is made of). And no, not the crap you buy at pharmacies or mass chain stores. Good stuff from the local health food/supplement store. Take 1 multi and fish oil pill with at least your breakfast, and whatever you have after the workout. You need food in your stomach in order to digest vitamins properly, and the fat from the fish oil will help digest the fat soluble vitamins, too. You take one after the workout because believe it or not, exercising releases free radicals, which the anti-oxidants in your vitamins will help fight. Take a scoop and a half of the way protein with a heaping teaspoon of pure/straight glutamine powder (5g) 30 min after the workout. This is the point where your blood vessels are dilated in an effort to pump more blood (which shuttles nutrients) into the damaged muscle tissue from the workout (yes, you are literally trying to DESTROY your old muscle tissue by lifting). That means your metabolism is 2 - 3 times higher at this point, and anything you consume will be sucked up like a sponge. Good time to feed your body all those aminos (from the protein) that it's going to need to start the repair process of bringing back your torn muscle tissue stronger/bigger/tighter than before. The glutamine is just helping out that process further since it's 60% of what your muscle tissue is made of.
Everything else is unnecessary garbage that you don't need right now, if ever. For example, N.O.-Xplode, Jack3d, and all these pre-workout crap drinks that are so popular right now are just fancy Red Bulls. The amount of creatine, arginine, beta-alanine, and all the other IMPORTANT ingredients (in the sense that they're something other than stimulants) are virtually non-existent, thus why everything is always listed as a "proprietery blend" on the labels as opposed to breaking down exactly what you're getting. The only thing in abundant enough amounts to do anything are the stimulants to get you wired for the workouts.