STABLES!
If you haven't do your stables ASAP (It replaces your barracks in early Garrison levels.)
It gives you daily quests for 8 new mounts.
A Talbuk, Clefthoof, Boar, Hippo, Elekk, Wolf.
It also gives you an option for (achievement kind of thing) that gives you an Armored Wolf and an Armored Boar.)
It takes several days of daily quests to get some of the mounts, you should be working on them as soon as possible so that you can stop using Stables in your garrison early. (Although it's a great passive not being dazed when you're on your mount in Draenor and 20% movespeed and being able to pick herbs from your mount.)