The Jade Forest - Eastern and beginning zone. Level 85 - 87.
Valley of the Four Winds - Central southern zone. Level 86 - 87.
Krasarang Wilds - Southern shore. Level 86 - 90.
Veiled Stair - Bridge zone linking the Valley of the Four Winds and Kun-Lai Summit. Level 87.
Kun-Lai Summit - Northern zone. Level 86 - 88.
Townlong Steppes - Western zone. Level 88 - 89.
Dread Wastes - Southwestern zone. Level 89 - 90.
Vale of Eternal Blossoms - Central zone. Level 90, but can get to zone via quest at level 87.
http://wowwiki.wikia.com/wiki/Pandaria