Learning Cataclysm Herbalism
First, visit any trainer in the main cities of old Azeroth - just ask a guard, and learn Cataclysm Herbalism. (Orgrimmar, Stormwind, etc.)
1 - 75
If you have the [Sky Golem] mount, you should use it while leveling herbalism because you can pick herbs without dismounting.
You can leve to 75 in both of these zones below.