"You are supremely perceptive" (Proslogion)
God has knowledge as it is not physical, even if the way humans acquire it is. What God knows is "self knowledge"; God knows about creation because he is the creator and so he has complete knowledge of everything he has made (including us)
(On Interpretation 9) Propositions about future contingent events (those whose causes are not determined by past events) have no truth value- Leads to Open Theism (the view that the future is unknowable, even by an omniscient being)
Boethius (listed in spec)
Book V of "The Consolations of Philosophy"- worried that God's omniscience compromises his benevolence, as if he knows what we are going to do before we do it, it is unfair to punish or reward. Also, why doesn't he prevent humans from doing evil things before they do them, if he knows it is going to happen?
Boethius resolves these questions by deciding that past, present and future exist simultaneously for God, and though he can witness our choices, he cannot adapt what is going to happen in the future, as for him this happens at the exact same time as the future. God "transcends all temporal change".
However, the issue remains, if this is the case, how does God answer prayers? The only possiblity is that prayers have eternally been answered.
Luis de Molina
God knows all the possibilities of an outcome, having the capacity of middle knowledge, so we can act freely, as all God knows is what possible choices we may make, He does not influence them.
God is everlasting and therefore knows our past and present but cannot know the future. He simply makes an educated guess based on what he knows of us from past decisions we have made, thus free will remains.