I followed Jame's guides over at wow-pro.com for all my post-BC leveling. Since they were published, the XP requirements to level were lowered and RAF/heirlooms made available, so you always get ahead of the guides. IIRC I hit 70 in Nagrand. I did most of the quests in Hellfire (for the gear), then to Zangarmarsh and finished in Nagrand....maybe a few others here and there in Terrokar and Blades Edge, but not many. I don't think my team has ever been to Netherstorm or Shadowmoon Valley.