Wicca is very much a polytheistic religion as it recognizes the existence of many, many Gods and Goddesses. Many Wiccans would also be considered henotheistic in that they work with particular Deities while not denying the existence of others. And as GPS stated, Wicca is a modern religion; however, it looks to the ancient pre-Christian religions of Northern Europe for its model. You can read more about the antiquity of Wicca at http://www.spellsofmagic.com/read_post.html?post=533618
In British Traditional Wicca (ie: Gardnerian, Alexandrian, etc.) there is a specific God and Goddess who are honored in their practice. The names of these two Deities are oathbound and are never written down nor revealed to non-initiates.
If one is eclectic Wiccan one can work with any Deities to whom they are drawn. Nor are you limited to working with only one God and only one Goddess. In my personal practice I am a Priestess of Sekhmet, but I also work with Anpu, Tehuti, and Menthu.
It is generally recommended that in working with Deities one works within a specific pantheon or group of Deities from a particular culture. Some Deities do not like being paired with other Deities from a culture with which they once clashed. For instance, I would not try to mix a Deity from Celtic Britain with a Roman God or Goddess because of the ancient conflicts between their worshipers.
Of course when one is first starting out in Wicca it isn't necessary to identify with a specific God or Goddess at all. One can simply start by honoring the Triple Goddess and the Horned God. Simply referring to them as "Lord" and "Lady" is perfectly acceptable. Later you may find yourself drawn to specific Gods and Goddesses and develop a relationship with them and call them by their historical names.
An excellent book on the subject of personal relationship with Deities is "Devoted to You" by Judy Harrow.