http://www.theoi.com/Georgikos/Pan.html

Was the god of shepherds and flocks, of mountain wilds, hunting and rustic music? He wandered the hills and mountains of Arkadia playing his pan-pipes and chasing Nymphs. His unseen presence aroused feelings of panic in men passing through the remote, lonely places of the wilds.

The god was a lover of nymphs, who commonly fled from his advances. Syrinx ran and was transformed into a clump of reeds, out of which the god crafted his famous pan-pipes. Pitys escaped and was turned into a mountain fir, the god's sacred tree. Ekho spurned his advances and fading away left behind only her voice to repeat forever the mountain cries of the god.

Pan was depicted as a man with the horns, legs and tail of a goat, and with a thick beard, snub nose and pointed ears. He often appeared in the retinue of Dionysos alongside the other rustic gods. Greeks in the classical age-associated his name with the word pan meaning "all". However, its true origin lies in an old Arkadian word for rustic.

Pan was frequently identified with other similar rustic gods such as Aristaios, the shepherd-god of northern Greece, who like Pan was titled both Agreus (the hunter) and Nomios (the shepherd); as well as with the pipe-playing Phrygian satyr Marsyas; and Aigipan, the goat-fish god of the constellation Capricorn. Sometimes Pan was multiplied into a host of Panes, or a triad named Agreus, Nomios, and Phorbas.

BIRTH OF PAN

Homeric Hymn 19 to Pan (trans. Evelyn-White) (Greek epic C7th - 4th B.C.) :
"Hermes . . . came to Arkadia, the land of many springs and mother of flocks, there where his sacred place is as the god of Kyllene. For there, though a god, he used to tend curly-fleeced sheep in the service of a mortal man, because there fell on him and waxed a strong melting desire to wed the rich-tressed daughter of Dryopos, and there he brought about the merry marriage.

And in the house, she bares Hermes a dear son who from his birth was marvellous to look upon, with goat's feet and two horns--a noisy, merry-laughing child. But when the nurse saw his uncouth face and full beard, she was afraid and sprang up and fled and left the child. Then luck-bringing Hermes received him and took him in his arms: very glad in his heart was the god. And he went quickly to the abodes of the deathless gods, carrying his son wrapped in warm skins of mountain hares, and set him down beside Zeus and showed him to the rest of the gods. Then all the immortals were glad in heart and Bakkheios Dionysos in especial, and they called the boy Pan [derived from pantes meaning 'all'] because he delighted all their hearts."

Pseudo-Apollodorus, Bibliotheca 1. 22 (trans. Aldrich) (Greek mythographer C2nd A.D.) :
"Apollon, learnt the mantic art from Pan, son of Zeus and Thymbris."

Pseudo-Apollodorus, Bibliotheca E7. 39 :
"Some say that Penelope [wife of Odysseus] was seduced by Antinous [one the suitors], and returned by Odysseus to her father Ikarios and that when she reached Mantineia in Arkadia, she bore Pan, to Hermes."

Herodotus, Histories 2. 153. 1 (trans. Godley) (Greek historian C5th B.C.) :
"Among the Greeks, Herakles, Dionysos, and Pan are held to be the youngest of the gods . . . and Pan the son of Penelope, for according to the Greeks Penelope and Hermes were the parents of Pan, was [first worshipped in Greece] about eight hundred years before me [Herodotus], and thus of a later date than the Trojan war . . . Had Dionysus son of Semele and Pan son of Penelope appeared in Hellas and lived there to old age, like Heracles the son of Amphitryon, it might have been said that they too (like Herakles) were but men, named after the older Pan and Dionysus, the gods of antiquity;  but as it is . . . for Pan, the Greeks do not know what became of him after his birth. It is therefore plain to me that the Greeks learned the names of these two gods later than the names of all the others, and trace the birth of both to the time when they gained the knowledge."

Pausanias, Description of Greece 8. 30. 2 (trans. Jones) (Greek travelogue C2nd A.D.) :
"They say that Pan was so surnamed [Sinoeis] after a [Arkadian] Nymphe Sinoe, who with others of the Nymphai nursed him on her own account."

Pseudo-Hyginus, Fabulae 224 (trans. Grant) (Roman mythographer C2nd A.D.) :
"Mortals who were made immortal . . . Pan, son of Mercurius [Hermes] and Penelope."

Nonnus, Dionysiaca 14. 67 ff (trans. Rouse) (Greek epic C5th A.D.) :
"Two other Panes [in fact just Pan in his two aspects as Hunter and Shepherd], the sons of Hermes, who divided his love between two Nymphai; for one he visited the bed of Sose, the highland prophetess, and begat a son inspired with the divine voice of prophecy, Agreus (Hunter), well versed in the beast-slaying sport of the hunt; the other was Nomios (Shepherd), whom the pasturing sheep loved well, one practised in the shepherd’s pipe, for whom Hermes sought the bed of Penelope the country Nymphe. Along with these came Phorbas to join their march, savage and insatiate." [N.B. Phorbas means "giver of grazing," but is also a play on the word Phobos, "fear," the third aspect of Pan as the inspirer of irrational panic].

CHILDREN OF PAN

Ovid, Metamorphoses 13. 750 ff (trans. Melville) (Roman epic C1st B.C. to C1st A.D.) :
"Acis was the son of Nympha Symaethis and Faunus [Pan] was his father, a great joy to both his parents."

Statius, Thebaid 11. 32 ff (trans. Mozley) (Roman epic C1st A.D.) :
"[The army of the Seven Against Thebes is routed and the Thebans pursue :] Eurymedon pursues, with armour rustic and uncouth and rustic weapons in his hand and native skill to arouse panic terrors--his sire was Pan."

Statius, Thebaid 9. 318 ff :
"[The battle of the Seven Against Thebes was carried to the streams of the River Ismenos :] Crenaeus, the youthful son of Faunus [Pan] and the Nympha Ismenis, rejoiced to fight in his mother’s water--Crenaeus, who first saw the light in the trusted stream and cradled in the green banks of his native river."

Nonnus, Dionysiaca 14. 67 ff (trans. Rouse) (Greek epic C5th A.D.) :
"The rock dwellers came also from their self-vaulted caves, bearing all the name of Pan their father the ranger of the wilderness . . . they have human form, and a shaggy goat’s head upon it with horns. Twelve horned Panes there were, with this changeling shape and horn bearing head, who were begotten of the one ancestral Pan their mountain ranging father."

PAN, ZEUS & THE MONSTER TYPHOEUS

Pan was occasionally identified with the goat-fish god Aigipan who assisted Zeus in his battle with the monster Typhoeus. This was usually regarded as another divinity, however, from whose skin Zeus crafted his aigis shield. The pair Aigipan and Pan even appear together in one C5th BC Greek vase painting, indicating they were long regarded as separate divinities, despite their similar name.

Pseudo-Hyginus, Fabulae 31 (trans. Grant) (Roman mythographer C2nd A.D.) :
"Euhemerus [C4th B.C. mythographer] says that a certain Alex was the wife of Pan. When she was embraced by Jove [Zeus] she bore a son whom she called the son of Pan. So the child was called Aegipan, and Jove, Aegiochus (Wielder of the Aegis). Since he was very fond of him, he placed in memory the form of a goat among the stars."

Nonnus, Dionysiaca 1. 368 ff (trans. Rouse) (Greek epic C5th A.D.) :
"And goat-herd Pan who went with him [the hero Kadmos] gave Zeus Almighty cattle and sheep and rows of horned goats [during his war with Typhoeus]. Then he built a hut with mats of wattled reeds and fixed it on the ground: he put on Kadmos a shepherd’s dress so that no one could know him in disguise when he had clad his sham herdsman in this make-believe costume; he gave clever Kadmos the deceiving pan-pipes, part of the plot to pilot Typhaon to his death [and Kadmos disguised as a shepherd tricked Typhoeus into returning the sinews of Zeus]."

Nonnus, Dionysiaca 27. 290 ff :
"[Zeus addresses Athena :] He [Pan] once helped to defend my inviolable sceptre and fought against the Titanes."

Suidas s.v. Haliplanktos (trans. Suda On Line) (Byzantine Greek lexicon C10th A.D.) :
"Haliplanktos (Sea-roaming) : Thus Pan is called . . . because he hunted Typhon with nets."