Im just gonna say what I tell everyone.
Get your diet and training in order, then worry about supplements. Most people that have to ask what to take, shouldn't take anything yet. It also really depends on your goals, so make sure you have those in order too.
And one last thing, if you dont work your ass off, again, you shouldn't be taking anything.
If you got all that in order I would be glad to share the knowledge I have, just be a little more specific than "I want to build muscle mass".
Are you planning on being a competitive bodybuilder? are you just someone looking to get bigger? do you have any strength goals? fat loss goals?