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.
IMPORTANT! High level players will see the patch 8.3 version of Uldum. You can talk to Zidormi to switch between the new and old low-level phase of Uldum. (if you open the map, she will be marked with a white text bubble at Ramkahen)