XP Potions: The Elixir of Rapid Mind and Elixir of Ancient Knowledge no longer drop. They can be bought on the AH still but are way to expensive for it to be worth it. The Excess Potion of Accelerated learning is available from your garrison quartermaster but only works for level 91 to 99. As of Patch 8.1 you can also buy the 10% XP Potion Draught of Ten Lands.
Anyway, however you choose to get to the addon's menu, choose guide list and then pick the zone you want to quest in. There are some zones that will autoselect based on quests in your log, but not all guides or all quests are set up that way. (If you don't want to switch to a guide that auto-pops up choose "not now" or "never") As you can see in the screenshot, there are various categories of guides. Most max level content (such as Argus) is found in Achievements rather than leveling.
Azeroth paid a terrible price to end the apocalyptic march of the Legion’s crusade—but even as the world’s wounds are tended, it is the shattered trust between the Alliance and Horde that may prove hardest to mend. As this age-old conflict reignites, gather your allies and champion your faction’s cause—for Azeroth’s future will be forged in the fires of war.

Elixirs serve the same purpose as Flasks, but the buff expires if you die. You'll only use these between 1-70, generally speaking, until you can start buying Flasks which persist through death. Try not to die, and carry extras just in case. If you can't find an Elixir with the stat you want, look under scrolls, since they count as battle or guardian buffs as well.
BigWigs is the best boss mod available currently. It is extremely customizable, allowing you to change what is displayed on an individual boss level and how boldly you want each alert customized. BigWigs is typically the most accurate and periodically updated of the available Boss Mods. It does not require any setup at all, though there are a dizzying array of options and customizations should you wish to personalize your setup.
This level range opens a variety of zones from the Cataclysm expansion, which are spread across the game’s original continents, but it’s more efficient to head to the continent of Pandaria. You can spend the entirety of this level range exploring its uniquely themed zones and quests. The Jade Forest, Valley of the Four Winds, and Kun-Lai Summit are our picks, but all the zones are worth checking out.
Assuming, worst case, procs of 30 monelite ore, in my server they sell for 20g each, so 600g per proc. 5325 divided by 600 is 8.875 missions, rounded up, 9 procced missions in order to make even with pick costs. EVERYTHING after that is pure profit. Its important to remark that the chance is far from 100%, some people say as low as 10% to proc but I didnt find any hard data on this.
Jewelcrafting is a crafting profession that revolves around gems. You prospect various ores turning them into gems and cut the gems. The cut gems can be added to socketed items. In addition you can craft rings that can either be disenchanted or sold as gearr. The Legion epic and rare gems and rings all sell very well. The jewelcrafting panther mounts are the best old world recipes.

 Void elf - "Many have sought to harness the corruptive magic of the Void. Most who tried have fallen into madness. Determined to use this power for the good of Azeroth, Alleria Windrunner is the first mortal to succeed at defying the shadow's whispers. Coming to the aid of a group of her kin who nearly gave in to the darkness, Alleria has vowed to train these Void Elves to control the shadows within them and pledge their newfound powers to the Alliance."
Profit is only created if you make sure your costs are less than your earnings. This is not so much an issue for gatherers who simply trade in some time and effort to gain their wares, but for production professions, this must be kept in mind. Many high-end items that sell well require materials that cannot be provided by the gathering profession normally paired with your production profession. To craft these items, purchasing the raw material from the AH or another player becomes necessary. You must keep record of how much you spent to obtain these materials, or else you may price the finished product inaccurately, either too low that you sell it at a loss, or too high that you can't sell it all.

I highly recommend actually staying in the 20-60 range zones until you ding 62. The reason for this is that despite getting a slight penalty in experience for being over-level, the advantage of having flight will more than offset this. That, and WOTLK and TBC zones are the slowest part of the leveling process. Minimizing your time there as much as possible is worthwhile.
Once you get to about 200g, the theoretical limit of your profit virtually disappears. You now have enough money to start mass buying and reselling those players' goods who undercut everything by an extreme amount. Enchant mats are still a very good focus during this period, especially essences and crystals. You can now afford to buy several maelstrom and abyss crystals and wait until prices fluctuate to resell for a profit. A major strategy you can begin to employ is the multi-character trading and auctioning. If you come across 5 abyss crystals, get onto one character during peak hours and advertise a price 25-50% higher than average. When no one responds to this, quickly switch to another toon and offer the same 5 crystals for 10% lower than before. This will help to raise the median price because other sellers see what they may be able to get for their good. While they are cancelling and reposting, take this time to undercut their new prices, which is now more than you ever could have gotten before when prices were low. If you master this with BoE epics or more rare items, then you can make differences of thousands of gold.
I liked the little discount for the weekend special. I was used to buying other expansions that included a 30 game time card, this did not. However I was prompted to spend gold I had build up and saved, previously playing the game, and it cost me 117000 gold deducted from my combined characters on my old main server. Big download, so I had to wait to play it until the next morning. Gameplay is different, I was used to the old talent point system, alas I had 10 lvl 100 characters, max level garrisons and shipyard. I did the only thing thinkable without having to take time to vendor unusable items that I thought had meaning. Created the new class. Tutorial started at 98, to get you to 100 with a slow intro back into the game. Auction house prices are pretty high with how long this game has been around. I hope to play more soon, but not like the hardcore grind years past. All I know is I am spending remaining gold saved on biggest affordable bags, and whatever flight trainings to keep me moving fast. Game looks good, no lag, I already enjoy the storyline again.
Of course this is pure speculation, but who thought the token would be beneath 200.000 Gold again? But the only thing important for you is to calculate at what point you make profit by selling the tokens again. If you consider it, you should take the risk! Worst case scenario: You have a lot of battle.net balance to spend for Gametime, mounts, pets and boosts/services!