There are many minor gods and goddesses. Here are just a few:
Aegle: goddess of brightness
Strangely enough, Aegle's parents are Nyx and Erebus, the god and goddess of the night and darkness. She is one of the goddesses of the sunset.
Aeolus: god of wind
Cousin of Poseidon, Aeolis controlled the winds from his island. He is best known for trying to help Odysseus reach Ithaca.
Chloris: goddess of spring flowers
Roman Name: Flora
Chloris is not only the goddess of spring flowers, but also of gardens and perpetual youth.
Eileithyia/Ilithya: goddess of childbirth
Roman Name: Lucina
Eileithyia is the daughter of Hera. She helped her mother in a conspiracy to make Hercules born after his cousin, Eurystheus, therefore giving the throne to Eurystheus.
Eris: goddess of chaos and discord
Roman Name: Discordia
Eris loved to create discord and anger among the other gods, so she was often left out when parties or celebrations were held. Her plots for revenge usually involved all the gods, and plenty of people too. Her best scheme appears in the story of the Iliad.
Eros: god of love
Roman Name: Cupid
Eros is the son of Aphrodite. He shoots arrows of love and hate into whoever she commands. Once, he fell under the spell of his own arrow after accidentally pricking himself. Best known by his Roman name, Cupid, Eros represents love or hate at the first sight.
Erythia: goddess of scarlet
Erythia, sister of Aegle and Hesperethusa, is one of the goddesses of the sunset. She helps to guard the golden apples of the gods.
Hesperethusa: goddess of the sunset glow
Hesperethusa is another goddess of the sunset, along with her two sisters. She also helps guard the golden apples of the gods.
Hypnos: god of sleep
Roman Name: Somnos
Hypnos is the son of Nyx and Erebus. Unlike his sisters, he really doesn't so much except lay around and sleep. His son, Morpheus is the god of dreams.
Iris: goddess of the rainbow
Like Hermes, Iris acted as a messenger for the Olympian gods, especially Hera. She delivered messages between the heavens and earth, which was beautifully symbolized by a rainbow that appears to bridge the earth and the sky.
Pan: god of shepherds, and other minor gods
Roman Name: Faunus
Pan is best known as a goat-man who sits in the fields and plays his pipes. He also keeps dogs, and gave two of his best to Artemis on Zeus' command. Pan usually receives sacrifices from shepherds and farmers.
Persephone: goddess of plants
Roman name: Proserpina
Her mother is Demeter, the goddess of all that grows from the earth. Persephone is also the queen of the underworld, given to Hades as a gift from Zeus.