God doesn't get any lines in the Book of Daniel, but he's the hidden Master, pulling all the strings, controlling every event in the story as it moves along. Though he's the secret Wizard of Oz behind the scenes, clicking the switches, God seems to hang back a little in this book. He's not exactly stopping by to eat a picnic lunch with Abraham. In fact, he doesn't have any direct speaking lines in the Book of Daniel at all.
But Daniel does get to see God. It turns out that God—or the appearance of God that Daniel is allowed to see—looks like an elderly man, or an "Ancient of Days." His clothing is "white as snow, and the hair of his head is like pure wool." As in other parts of the Bible, God is really into fire—his chariot is made of fire, the wheels are made of fire, and there's even a stream of fire—maybe representing the Holy Spirit that flows forth from God's presence.
The Book of Daniel doesn't give us a direct sound-bite from God, but it does say that Daniel saw God judge and destroy the arrogant, talking horn that symbolizes a future persecutor of the Jews: the Greek king Antiochus IV Epiphanes.
Commentators like Jack Miles—an ex-Jesuit who wrote a Pulitzer Prize-winning biography of God—see God as seeming kind of tired or shy or something in this book. He's hanging back, just waiting to see what happens. But considering that he's in control of history, he probably already knows what's going to happen. So, hey, cut God some slack, Jack Miles. Can't God just chill out sometimes and let Gabriel and Michael do all the cosmic warring?
Overall, a big part of Daniel's message is that God's kingdom lasts forever, and all the other ones are bound to fall apart. You see that reflected in the dreams he needs to interpret, and in the far-out visions he has.