The Cloth Quartermasters can be found in every major city, such as in the Darnassus, Ironforce and so on . The easiest way to find the quartermaster is to ask a guard to direct you to the profession trainer for tailoring. You will find the cloth quartermaster is in the same location. The only exception is the Trolls and Gnomes, who do not have their own cities. The quartermaster for the Trolls can be found in Orgrimmar in the Valley of Spirits. The quartermaster for the Gnomes is located in Tinkertown, within Ironforge, but please note, only gnomes and dwarves can ride the mechanostriders of this faction.
Taurens should be aware that their large size bars them from riding the skeletal horses of the Undercity, the raptors of the Darkspear Trolls, or the hawkstriders of Silvermoon. It is pointless for them to raise faction with these groups, as they will be unable to obtain these mounts.
Other factions who allow mount purchase at exalted are The Mag'har (H) and the Kiurenai (A) in Nagrand, the Netherwing of Shadowmoon Valley and the Sha'tari Skyguard at Terokkar and Blades Edge. Faction for these groups can be obtained through repeatable quests. Those with exalted Cenarion Expedition reputation can purchase a Cenarion War Hippogryph for 1600 wow gold.
Differing groups have some advantages in the race to 50. Engineers can make mechanical rides. Tailors will be able to make a variety of flying carpets when Wrath of the Lich King is released. Paladins, Warlocks and Deathknights have their summoned mounts. Those who PvP are able to purchase or achieve special mounts through the PvP reward system.
A variety of bear and wooly mammoth mounts will come along with the release of the new expansion. There are reports from the PTR of a Traveler's Tundra Mammoth which can carry three riders and comes with its own vendors for repair, resupply and selling all that vendor dross that accrues in one's packs.
There are seven rare drops from bosses: the Deathcharger from Stratholme, the Swift Zulian Tiger and the Swift Razzashi Raptor from Zul'Gurub, the Fiery Warhorse from Karazhan, the Raven Lord from heroic Sethekk, the Swift White Hawkstrider from heroic Magister' Terrace and the Ashes of Alar from Tempest Keep. Congratulations to you if you managed to score one of these.
There are reports of a new mount that will drop with this year's Hallow's End event. There is a Zhevra mount that comes through the Recruit a Friend promotion.
If you hurry, you might even still be able to get an Amani War Bear. But time is running out. This mount comes from beating the timer to the fourth chest in Zul'Aman. It will not be available once the next update goes live. The clock is ticking on this one and may be behind us by the time this article is published.
There are a number of different colored Qiraj Resonating Crystal mounts, which are only usable in AQ 40. It is doubtful these will count toward the 50 mount achievement for Leading the Cavalry.
So mount up all you collectors of the various rides of Azeroth.