According to a player who had hands on time with the Alpha build, players in each faction will start in starting zones like other MMO's. http://www.rpgamer.com/news/Q4-2012/102212a.html For example, in the Ebonheart Pact players start on a small island northeast of Skyrim called Bleakrock. http://i.imgur.com/BVKNp.jpg to get an idea of where Bleakrock would be. Before being allowed to the mainland new players must complete the main quest of the island, and even as the starting area there are still "many side quest to be tackled" according to the player. Also he claims that Cyrodiil is rouchly nine times larger than one of the larger starting areas.
The article also notes that Cyrodiil is "a high level area" which is to be assumed that as well as the threat of death via PvP the province contains high level and difficult A.I enemies. Of course the introductory starting zones like other MMO's will contain low level easy mobs. I imagine that certain areas of each province will contain easy, moderate, and difficult zones, for example scaling the Throat of the World in Skyrim could be hazerdous and full of high level enemies. This will help keep most low level players from wanting to rush from starting areas to Cyrodiil or other well known locations.
Discuss this information about the map and how zones are being handled below.