Learning how to play a mage in World of Warcraft is actually a bit easier than many of the other classes and this also makes leveling a mage quite a bit faster once you understand how the class works.
A mage is a cloth wearing class and this means seperation from your enemy is the number one element to survival.
Players first learning how to play a mage in WoW often ask what is the best talent build and although usually one of the trees has a bit of an advantage over the other 2 at high levels, while leveling all three are very viable options.
Most long term players will recommend a new mage use the frost tree simply because it offers more survivability than either fire or arcane.
This will certainly help as new mages learn to master the art of seperation.
The key stats when building a mage in World of Warcraft are certainly intellect first and foremost. You will always want to look for cloth gear that has intellect as it increases your mana pool as well as your spellpower which increases the overall damage you are able to deal out.
Aside from intellect your secondary stats are going to greatly depend on the talent tree you decide to follow. Hit is certainly critical for all builds but is not as much of a factor until higher levels when you will need to be capped.
Arcane mages will focus on haste after hit because they have inherent built in critical strike rating while a fire or frost mage will tend to lean a bit more towards gear with critical strike to deal out larger critical hits more often.
Professions for those looking to learn how to play a mage in WoW offer several options and a mistake many new players make is not understanding there are critical stats offered by ach profession.
Enchanting allows the mage to enchant rings with intellect while jewelcrafting allows for special gems that offer higher levels of intellect that non jewel crafters cannot use. Tailoring offers the ability to craft your own gear and apply special cloak enchants at higher levels as well.
You can also get special enchants from leatherworking and a critical strike bonus from leatherworking although these professions are not that great of a choice for a cloth wearing class.
The tailoring / enchanting combination is probably the best choice for those learning how to play a mage in WoW because you will get a fair amount of cloth drops as you are questing that you can use to make gear as well as disenchant useless gear drops for the materials you need to enchant your own gear.
It is a nice profession combination that allows a mage to level professions without going out of their way for materials while trying to level.
The biggest impact on a mage or any other toon in World of Warcraft is proper selection of a good Mage Leveling Build and the proper assigning of those talent points as you level.
The frost mage leveling build is the best place for a new player to start although I highly recommend trying them all as you level to get a feel for how you like playing a mage in Warcraft.