Keep in mind that these quests are optional, and are not necessary to continue leveling and capturing companions. They are also account-wide, so if you complete the quest chain on one character, you will not be able to complete it again on another. However, any progress that you've made will be saved and you can pick up where you left off in the quest chain on another character. The dailies that you've unlocked will also be accessible by all your toons.
When it comes to levelling the Priest Class from 1-60 fast, XP grinding locations is only half the battle. You will need to make sure your weapon does enough DPS so that you can clear these mobs fast enough, it should also be noted that monster should be around your level to make sure to gain the 100% XP Reward. The Level your character should be before you start that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and the Orange Color for Horde [Lvl 35-39]. The Mobs you are looking for in that specific area names are Bolded [Mob Name].
The Horde 12-20 (Barrens + Stonetalon Mountains) guide has been rewritten and revamped.  In addition, there has been numerous tweaks to the speedrun route to make things faster and easier to follow.  Also, in case you haven't noticed I am now adding about 40% more info per step and redoing all the images.  Unlike with my previous vanilla guides, I am now giving a brief explanation of where to go and what to do with each step along with any other helpful tips.
The priest was considered the best overall healer in vanilla WoW. Priests had the biggest selection of healing and defensive spells which could be used in various different situations. Due to this fact, Priests had an easy time finding groups and guilds. If you’ll embark on leveling priest, expect some random whispers from other players inviting you to join their group as a healer. Shadow Priests were also considered as one of the best duelists in the game boasting with serious damage and healing.

Sorry! No addons (unless some are made specifically for the new release of Warcraft Classic). Also, Bidding Is A Thing.  There were bidding wars for the most expensive items on the AH, which you can only find in IF and Org. There might be bidding wars for the rarest of items on trade chat or the realm forums, for things such as the Hide of the Wild pattern. This drops from Dire Maul, Knot Thimblejack, by the way.

While they often played the role of villains in Vanilla WoW, even going so far as to work alongside the elemental lord Ragnaros, the Dark Irons have recently undergone a bit of a redemption arc. The Dark Irons have reunited with their Bronzebeard and Wildhammer cousins. Currently, dwarves are governed by a council consisting of representatives from all three factions, known as the Council of Three Hammers.
1. Vue d'ensemble de la classe Voleur 2. La meilleure race pour Voleur 3. Astuces leveling pour le Voleur 4. Les poison du Voleur 5. Addons pour Voleur 6. La meilleure spé pour le leveling 7. La spé alternative : « Frontstabbing » 8. Rotation optimisée pour le leveling 9. Stats conseillées pour le leveling 10. Liste des meilleures épées 11. Liste des meilleures dagues

Occasionally it's also been proposed to re-randomize all the gear. We didn't have best in slot lists back then. People weren't starting out as a fresh level 1 character with a complete list of which dungeons to run at 60 in order to gear as quickly and efficiently as possible. Now, all that data is available. If gear were re-randomized then all of those lists would become useless and thing would be close to how they were. Which is a more important part of the "vanilla experience?" the fact that item X from boss Y has exactly Z stats on it, or the voyage of discovery? Personally I think that voyage is way more important. Do you remember how many points of which stat on the ring or whatever that Darkmaster Gandling drops? I don't. Would it kill your experience if the BiS for every class were in a different dungeon so people had to actually play to figure it out rather than simply consult a spreadsheet? I don't think it would. For that matter, it probably wouldn't be a bad idea to handle it intelligently so that the better gear is in later dungeons. I remember there because some weird cases where level 40ish gear was better than anything that dropped in level 60 dungeons.

Before work began on World of Warcraft: Classic, it was only possible for players to experience the original World of Warcraft by using private servers, which are illegal, often have stability or corruption problems, and generally are very imperfect recreations of the authentic World of Warcraft experience. As much as Blizzard has been aware of the desires of their community, until recently it seemed impossible for them to emulate Classic servers due to the technical hurdles of essentially having to run two massively multiplayer online games side-by-side. A breakthrough was then achieved that made it possible to run Classic servers on the modern architecture of current World of Warcraft servers.
I think you are referring to the Env Bert strat I have linked. Basically I agree. But you might have noticed that I already had added min power to pet #2, in order to exclude some of the substitutes. Though, I didn’t wan’t to do the same with the Blazehaound (pet #1), because I think the strat is doable also with a suboptimal breed. But maybe you are right and I should just exclude any non-P/P breeds.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.