Short answers, pulled from the story.
Tolkien's Dwarves in Middle-earth were inspired by two main sources: the dwarfs of Norse mythology and his reading of medieval accounts of Jewish history. Norse myth gave them their affinity with mining, metalworking, and crafting. The medieval image of Jewish diaspora shaped their dispossession from Erebor and Moria, their private language, and their calendar.
Tolkien explicitly said so. In a letter, he wrote of thinking of the Dwarves "like Jews: at once native and alien in their habitations, speaking the languages of the country, but with an accent due to their own private tongue." In his last interview before his death, he said the Dwarves' language was "Semitic, obviously, constructed to be Semitic."
Dwarves speak Khuzdul, created for them by the Vala Aulë. Tolkien modeled Khuzdul on Semitic languages, giving it a root system of consonant clusters from which words are formed by inserting vowels, a feature of Hebrew and Arabic. The Dwarves kept Khuzdul secret and did not teach it to outsiders.
The Dwarves were created by Aulë, the smith among the Valar, who made them in secret without Ilúvatar's permission. Because they were made by a Vala rather than Ilúvatar himself, they initially lacked souls; Ilúvatar later granted those souls. The seven Aulë made became the Seven Fathers, each founding one of the seven Dwarf clans.
Dwarves in Middle-earth typically live around 250 years. They are still considered children in their 20s and striplings in their 30s, and they begin having children only in their 90s. No more than a third of Dwarves are female.
John Rhys-Davies played Gimli in Peter Jackson's live-action Lord of the Rings trilogy, giving the character a Welsh-derived accent. In Ralph Bakshi's 1978 animated adaptation, Gimli was voiced by David Buck.