For those of you new to the game, Druids are a great class for people who like to enjoy aspects of every class or don’t have the time to roll multiple levels 80 characters. Plus, let’s face it, using Typhoon on unsuspecting players is good clean fun. For leveling, you will most likely want to go Feral for leveling. This is because cat form has quick clean kills, and can “assassinate” higher-level mobs and run away.
At a lower level for trash mobs you can simply target them, cast Wrath, cast Thorns to bind them, cast Wrath twice more, then either cast Moonfire to finish them off, or turn to Bear/Cat Form and melee them down. This is one of the positive aspects of the Druid. They are able to utilize both their mana bar well, and when the mob reaches them they can take down the rest of their health in a melee form.
At level 40 you have the possible option to go Balance since you acquire the Moonkin form. This will be slightly less efficient than leveling as a Feral Druid, but it will help break up the boredom and is only slightly slower. Another bonus of the Druid class is that they are significantly better at farming mining and herbalism, due to their flight forms. So, I would suggest taking one of these two professions.
Anyways, I personally would advise rolling Horde if you want to be a Druid. This is because most abilities of druids are needed by the Horde more than the Alliance. Horde usually has the need of healers more than that of Alliance. Either decision should not be taken lightly and is more of a personal choice than a statistical choice.
Being a Druid, you are slightly gimped hearthstone wise since you only have your trainer in Thunder Bluff, so don’t count on being able to visit Orgrimmar too often. Thunder Bluff reputation comes easy for you, which is nice because you easily get Orgrimmar reputation from daily quests. One downside is that young alliance players often /moo at you, which get be either amusing or frustrating depending on your personality. Besides, who doesn’t want to heal looking like a tree! Most players also agree that the Dire Bear form’s /dance is AMAZING.
Want to gank some noobs at Ironforge? Go Cat form. Want to fly around at 310% speed? Go Flight Form, Want to tank like a beast with awesome fur? Go Dire Bear form. Want to throw people off bridges? Go Moonkin form. Want to be awesome at everything? Roll a druid.