There can be nothing "new" to God. All created effects pre-exist in God’s will. God’s will is in perfect accord with his knowledge. God’s will is the efficient cause of all things, so all created things pre-exist in God’s knowledge. Will is the inclination to put into action what one knows. Therefore, all created effects flow from God’s will.
Given that God knows Himself perfectly, He must know perfectly all the different ways His perfections can be shared by others. Within the essence of God there is all the knowledge of all possible kinds of things God's will could actualize. Hence, God knows all the particular things that could ever be actualized. In other words, God knows all possibilities.
It makes no more sense to say God has to be temporal in order to relate to a temporal world than to say God has to be a creature in order to create.
Endless time is just more of an elongation of time. But eternity differs qualitatively. It differs essentially, not merely accidentally. Eternity is an essential, changeless state of being that transcends moment-by-successive-moment reality.
When time changes, God’s knowledge does not change, since God knew it in advance. God knows change, but not in the way we know change. We know change in successive frames of time. From eternity God knows the whole of before and after equally vividly.
God knows the same things we do, but God does not know them the same way we know them. Our knowledge is discursive, as it moves from premises to conclusions. In human knowledge discursiveness is twofold: One thing is known after another, and one thing is known through another. God does not know things sequentially, since God is timeless and knows all things eternally equally vividly. God does not know things inferentially, for God is a simple being (simpliciter) and knows all things through the oneness of Himself. Hence, God cannot know anything discursively (sequentially, from topic to topic), since discursive knowledge implies a limitation to consider one thing at a time on the part of the knower.