Short answers, pulled from the story.
The Homeric Hymns are a collection of thirty-three ancient Greek poems and one epigram that praise deities of the Greek pantheon and retell mythological stories. They were composed mostly between the seventh and sixth centuries BCE, though the Hymn to Ares may date as late as the fifth century CE.
Modern scholarship has established that Homer did not write the Homeric Hymns. Although they were generally attributed to Homer in antiquity, and share the same dialect and dactylic hexameter as the Iliad and Odyssey, most date to the seventh and sixth centuries BCE. Ancient doubters included the rhetorician Athenaeus, writing around 200 CE.
The Homeric Hymns were first published in print by the Florence-based Greek scholar Demetrios Chalkokondyles in 1488-1489. The first English translation was made by George Chapman in 1624.
The Hymn to Hermes is the longest, with five hundred and eighty surviving lines. It narrates the first three days of Hermes's life, including his theft of Apollo's cattle and his invention of a tortoiseshell lyre.
The Hymn to Demeter and the first Hymn to Dionysus were preserved in a single manuscript, the Codex Mosquensis, written by Ioannes Eugenikos in the first half of the fifteenth century. Both were lost after its creation and remained unknown until 1777, when the philologist Christian Frederick Matthaei discovered the manuscript in a barn outside Moscow.
Lucretius, Catullus, Virgil, Horace, and Ovid all drew on the Homeric Hymns. Virgil used the Hymn to Aphrodite and the Hymn to Hermes in his Aeneid, composed between 29 and 19 BCE. Ovid made the most extensive use, referencing several hymns in his Metamorphoses, published in 8 CE, and in his Fasti.