Parentage:
He is the son of Zeus and a Titaness named Leto, and the twin brother of Artemis.
Consorts & Children:
Through the mortal Coronis, he's the father of Asclepius, god of medicine and healing, and by Hecuba, wife of King Priam of Troy, he fathered the mortal Troilus, who was killed by Achilles during the Trojan War. Also notable among his love affairs are the nymph Daphne, who had her father Peneus, a river god, turn her into a laurel tree to escape Apollo's affections; and Cassandra, Troilus's half-sister to whom Apollo taught the art of prophecy. However, when Cassandra spurned his advances, he cursed her so that none of her predictions would be believed.
Notable Stories Involving Him:
As the god of prophecy, he established many oracles, most notably the one at Delphi, and as the god of truth, he's incapable of lying. In his aspect as sun god, he drives a chariot through the sky each day, dragging the sun with it.
Sacred Symbols:
As the god of music and poetry, Apollo is often seen with a lyre, which was given to him by Hermes, and is considered the leader of the Muses. In addition to the lyre, bows and arrows are his attributes, and the dolphin, swan, crow, and laurel tree are sacred to him.
Apollo Around the World:
His Roman equivalent is also named Apollo, though he's also been identified with the Greek Titan Helios and the Roman Sol.
SOURCES: Greek Mythology.com, Mythweb, Encyclopedia Mythica, & Wikipedia