Timing marks

Okay, so I just rebuilt the engine on my vehicle. Now I'm at the timing chain and crankshaft and camshaft sprockets and what do I see, a third sprocket. Something called a balancer sprocket. I have to set this in time too but how? Do I line up the crankshaft, camshaft, and the balancer all together or separately? If I do can someone explain to me how to do this step by step. I would greatly appreciate it.