Players should keep in mind if you want to gain the full 100% XP reward from killing mobs they will need to close to your current level. With that in mind below we list each location you can grind levels 1-60 with the Mage class. The Level your character should be before you start farming in 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 levels 50-60 guide has been rewritten and revamped. My 1-60 Horde leveling guide is now completely updated for the 1.12 Drums of War patch. As you can see it is about 15% larger than the 40-50 guide (single largest guide page yet). There is also a lot of route changes. I moved the entire Silithus section from level 55 to level 58, which allowed me to include a lot more quests for that zone. There is also a lot of other improvement to the route, including adding a lot more quests into the guide, mostly from Moonglade, Silithus and Eastern Plaguelands. This will make the final level 59 grind much shorter.
If possible, avoid purchasing Gear from the Auction House - Ideally, you should be able to achieve level 60 without buying anything from the Auction House. This way you will save Gold, but possibly make leveling a bit harder for yourself. If you badly require an Item upgrade, and the suitable Item is available on the Auction House for a low enough price - buy it, but only if you think that the investment will pay for itself in one way or another (the main exceptions to the Auction House ban Rule are Weapons and Wands, as they make leveling much faster, and pay for themselves by allowing you to chain-kill more mobs without Eating and Drinking, which saves Gold and time).
There are 5 Dreaming whelps and 7 adolescent whelps spawns, They drop the small flame sack which sells for a decent amount at auction house or can be used to make fire protection potions. The sacks have around 10% chance to drop and it's one of the main reasons you want to grind here. On top of this you'll get lots of grey items, green and blues with a higher chance than your average mob. If you are not aware yet, dragonkins have the best loot table in the game while having less HP and armor... making them easier to kill, assuming you're not fighting elites...