You could have a leaking head gasket into the combustion chamber, are you losing coolant? Pull the the plugs and look for a burnt "white" coloring on it. Coolant in the combustion chambers would yield white smoke from the exhaust, as well as a "sweet" smell due to the antifreeze being burned off. You may also experience loss of power and coolant loss depending on the severity of the head gaskets condition. Another thing you can do is have it checked on a scope, by a mechanic, for really HIGH hydrocarbon emissions.
I REEAALLLYYYY hope this is not it, I don't even want to imagine if its a cracked head?
but I will have a big ol' checklist to go through tomorrow! Rock on! (really excited to see the condition of the spark plugs now! IF there isn't a "burnt white", does that mean the coolant leak is out the window?
I was so concerned about the smoke itself, that I can't say I noticed much of a smell of it *face palm*
I looked up a few articles/posts on how to check the radiator's fluid level, but couldn't find a real "precise" answer... How can I tell it's level? Is it safe to over fill since it can drain off itself?
