Is God a male God or a female Goddess? Well, it's both and none.
The highest characteristic of God is unity. God/Goddess is the oneness of all that is - and then some. Where we see two pieces, God sees a single whole. In this sense, it doesn't matter if we refer to God as 'God', 'Goddess', or 'Great Flying Spaghetti Monster', because all words have their limitations and we're bound to get it wrong one way or the other. That's why some civilizations and religions refer to God as 'that which has no name'.
That said, even if God at the highest level is unity, God employs duality in creating the world, since complementing dualities are the basic forms of relation. Think of it as a pendulum that swings back and forth, or that a foreground also has to have a background for it to have meaning. Through such dualities God can give creation a 'pulse' which makes it change all the time and carry it forward.
One such duality that we humans naturally recognize is the duality of male and female. We see some ideas, concepts, energies and motions as male, and others as female. Since most people can categorize themselves as either male or female, in our personal relationship with God it makes sense for a woman to see her as Goddess and for a man to see him as God. Furthermore, since we too have both female and male types of energies within us in different ratios, we can relate to God/Goddess in both ways if we choose to (or in any way that makes sense to you).
If the Sun is God energy, Earth is Goddess energy. If darkness is allowing Goddess energy, light is radiating God energy - and so on. It's okay to try to associate one thing with another in order to understand it more closely, just remember that whatever way you turn it, God/Goddess is the unity of all.