No, God is not a man. She is not a woman either. The idea that a single person with human emotions, thoughts, flaws and limitations also has infinite power to control the universe is pretty ridiculous. To make an analogy, it's like building a long stairway from earth to heaven, and bothering to construct only the first and last steps of the stairway. Such an idea has a huge gaping hole in the middle.
Even though God is not a single man, there is undoubtedly a connection between God and all of humanity. We live and breathe God, even if we don't notice the divinity around us and that we are a part of it.
How can a man (or woman) bridge the gap and become closer to God? The trick is to build the steps one at a time and not expect God's angels to grab you and fly you up with no effort on your part. Power is not something that you simply attach to a human ego.
To gain power first you have to develop the integrity to wield it. With no responsibility, the power of God burns like fire and makes you scream like you're in hell. Without a sense of balance, order cannot be made out of chaos. Without Love, parts cannot be made whole. Without transcending the ego, one cannot be human and God at the same time.
There are several words to describe a human who is to become God, such as: avatar, übermensch, bodhisattva etc. God is all and all is God - the difference between such a spiritually fulfilled person and a normal human is simply the degree to which we are aware of the oneness and Love of God.