Milky oil, oil in the coolant, white sweet smelling exhaust, your coolant blows out the radiator cap violently if you run the engine with the cap off and it is cool. -Never take the radiator cap off if it isn't cool.
normally you will have white smoke coming from the exhaust. If you have antifreeze in the cooling system, the exhaust may smell sweet. The engine may have water in the oil or may run hot.
You will either see coolant around where the head sits on the block or,while smoke coming put of the tailpipe. at that point coolant will be getting past the head an leak in to the cyliner or cylinders,also chech your spark plugs and do a test to check for exhaust gases coming out of your radiator
The engine will be leaking oil more than normal. To check the amount of oil leaking in a certain amount of time put a large piece of cardboard under the car and check the size of the oil stain during a set amount of time.