Yes, the wikipedia page has very good details about this.
They were held in honor of Zeus, and the Greeks gave them a mythological origin. The first Olympics is traditionally dated to 776 BC.
There were many events in Ancient Olympic games. There is one page available which contains the list of victors in events, but it is not in very good condition. You can see here
There were several participants in the Olympics events, some of them are mentioned here-
1- Cynisca of Sparta (owner of a four-horse chariot) (first woman to be listed as an Olympic victor).
1- Diagoras of Rhodes (boxing 79th Olympiad, 464 BC) and his sons Akusilaos and Damagetos (boxing and pankration).
2- Leonidas of Rhodes (running: stadion, diaulos and hoplitodromos)(His record of 12 individual olympic titans was broken in 2016 by Michael Phelps who received his 13th original title.).
1-Astylos of Croton (running: stadion, diaulos and hoplitodromos).
2-Milo of Croton (wrestling).
3-Timasitheos of Croton (wrestling).
From other cities/kingdoms:
1-Koroibos of Elis (stadion, the very first Olympic champion).
2-Orsippus of Megara (running: diaulos).
3-Theagenes of Thasos (boxer, pankratiast and runner).
4-Alexander I of Macedon (running: stadion) .
1-Tiberius (steerer of a four-horse chariot).
2-Nero (steerer of a ten-horse chariot).
3-Varastades, Prince and future King of Armenia, last known Ancient Olympic victor (boxing) during the 291st Olympic Games in the 4th century.
Apart from this there is another source which tells about the number of events and it's winners. The list can be seen here