Please Help Coolant Problem....

[danger69]

Okay I've been searching for an answer for quite a bit but no answer. I firsted noticed a problem with my temp gauge. It wouldn't go up at all? And once i turn off the car I noticed that the coolant on the overflow tank is bubbling. I checked my oil and its still okay no milky look or anything. Next day I start the car and of course temp gauge is not moving. But after 5-10min I hear a pssssshhhh sound. And I see coolant leaking from some where *which I still do not know where, but do know its not near the waterpump. Its some where under the intake manifold from what I can guess*. I then wait till it cools down and I open the radiator cap and pour in some water since it looks dry. I leave the cap open and turn on the car and about 5min steam starts shooting out. What does that mean? And the water that I poured into the tank went to the over flow tank. Also the upper radiator hose is hot while the bottom one is very cool. Reason??? Please help.