Like with addons in the current game, you just need to drop any of these addons into the addons folder — find it under /Interface/AddOns/ in the Classic beta folder, which is in your World of Warcraft folder by default. Then once you log on to the game, you’ll want to make sure that the addons are enabled via the menu option on the character screen.
Dugi Guide, I have found, is a great solution for all those looking for an elaborate WoW Guide. Besides having the always popular leveling guides for both Horde AND Alliance additionally you get a gold earning guide, which is also the most popular Warcraft product. On top of this he covers a multitude of topics from macro’s, talent builds, profession guides and even more.
We have no idea what implications this might have and whether or not it even indicates anything, since Patch 8.2 is still in testing and a Tuesday launch is more than unlikely due to Essence tuning and Azshara's Eternal Palace, which is supposedly coming shortly after launch. Blizzard said they wouldn't be delaying the new raid like they did with Battle of Dazar'alor.