This is actually two questions in one: "What does God want in general?" and "What does God want from humans?"
God wants to experience existence fully. What does this mean for God? I don't know, but even if comprehension using the mind is difficult, comprehending through the heart by looking around the world and feeling the beauty of it all does give a glimpse of what kind of fulfilledness God might feel.
There are so many forms and shapes and patterns for God to experience itself through. Even if God is oneness, it is hard to experience oneness without creating different relations and experiencing different facets - and then making it whole again. (This is the pulse or breath of God.)
And what does God want from humans? God wants for us what we want for ourselves.
Some people go around telling other people what God wants from them and interject themselves as middlemen between God and his 'sheep'. In reality, this works out as a game of broken telephone, where a potentially well-meaning message turns into a call for murderous hatred. You alone can decide what you want for and from yourself, and God will support you in that decision.
The reason why most people don't understand this simple concept is that they might say one thing but act in a completely different fashion. For example, saying "I want to be rich and healthy" and then spending frivolously and living an unhealthy lifestyle creates confusion within. Of course, even in this case God supports that which is most true for ourselves, and we end up creating misery and suffering. Turns out many people find suffering to be fun and a true expression of themselves - go figure.