Hermes
Though Hermes had many tasks and responsibilities as a God, his main function was as the messenger to the Gods. Besides carrying messages, many of the Gods relied on him to help hide their own misdeeds. He was wore winged sandals for speed, and carried a caduceus (known today as a symbol of medicine). He was also involved in travel, good luck and fortune, gambling, creativity, astronomy, music, public speaking, medicine, literature and athletics.
Hermes also functioned as a psychopomp, leading the souls of the dead to Hades. Because as an infant, he snuck away from his mother and stole cattle from Apollo, Hermes is the patron God of thieves.
Hermes father was Zeus, but his mother was Maia (a Nymph). Most of Hermes' children are lesser known figures of Greek history, but he did father Pan, the wild nature. Pan's mother was either Penelope (wife of Odysseus) or Callisto (another Nymph). As with much of the lineages of Greek legend, it depends on which myths you are reading.
Hermes was in control of the elements, and was the patron God of alchemists. Even today, he is credited with founding the magickal practices of Hermeticism. Not a religion, this is an esoteric path that includes alchemy, Qabalah, and theosophy. He is sometimes associated with the Egyptian god of knowledge and writing, Thoth. It's believed that Hermes/Thoth created the Emerald Tablets, which form the basis of Hermetic thought.
In the Roman pantheon, Hermes was known as Mercury.

