The races from the Player's Handbook are all available.  If you want to find a likely starting location for your character:

**Humans**: anywhere

**Halflings**: Idee, Hollow Hills, Urnst, Ulek

**Eladrin**:  Celene, Spindrift Isles, Ulek, Sunndi, High Folk

**Elves:** Granwood Forest, Ulek, Vesve Forest, Celadon Forest, Nyrond

**Dwarves:**  Iron Hills, Irongate, Onnwal, Ulek, Ratik, Sterich, Glorioles  

**Tiefling**: anywhere, but mostly in the Great Kingdom and the countries bordering the Crystalmist Mountains and Hellfurnaces in the West.  There is rumored to be a Forgotten city of Tieflings in the Sea of Dust.  Some Tieflngs speaking a strange dialect have begun to appear in the easternmost countries recently as well.

**Dragonborn**: anywhere, but there is a rumored secret city in the Vast Swamp

**Half-elves:** anywhere, but most common where there are populations of Elves or Eladrin (as above)

The list is far from exhaustive, but should give you a choice of starting locations for character background