Disclaimer: Part 1: If you buy the guide through the links on this page I do get a cut. Part 2: With the guide I have leveled one Rogue from 70 to 90, another from 1-90 (yeah, two 90 Rogues,) a DK from 55-90, a mage from 1-90, and various others. Family members have leveled an assortment of other characters, some with little gear, others with full heirlooms and Recruit a Friend (3x XP.) So I confess, I like this guide. We all do.
Just before Battle for Azeroth goes live, you will want to log all of your characters out in the zone of Silithus so that you can acquire the quest to talk to Magni and obtain your Heart of Azeroth (refer to our Heart of Azeroth guide for more information about this item). This is the new artifact-type of piece of equipment that you will use for all of the Battle for Azeroth expansion. Once you acquire your permanent neck slot piece of equipment, get back to Stormwind or Orgrimmar to begin your scenario that leads into the introductory areas of Kul Tiras and Zandalar.