Wizards are unique in more ways than one. They can deal tremendous amounts of damage at their foes, even if those foes cannot get to the Wizard. They can Research and Enchant items, granting their wearers enhanced abilities. They can draw the very elements from around them, and concentrate them into potions. Their disadvantages, though, are fairly obvious: in close combat, they are fairly weak compared with Warriors, Monks, and even Rogues.
Wizards will need to focus on two main attributes: Intelligence, and whichever attribute corresponds with their chosen Element. (Strength for Srad, Dexterity for Athar, Constitution for Creag, and Wisdom for Sal.) Rather than shaping their attributes to suit their fighting style, however, I find the reverse often happens with Wizards: their attributes shape their fighting style. Srad mages, with their great strength, often have no problem finishing off a creature by bashing it on the head, for instance, while Athar and Creag wizards often don't worry about letting a creature get close, counting on their Dexterity to allow them to avoid attacks or on their Constitution to allow them to absorb them. Sal wizards, with their Wisdom, probably learn the correct way, though: stand far away, hopefully with a barrier between them and their prey, and let their spells do their work.
Arnljot, the Abel Tailor, sells the female Wizard's first-circle armor, the Magi-Skirt. Male Wizards will have to go to Rucesion to purchase theirs, the Gardcorp, from Huberto the Tailor. Upon reaching the second circle, all Wizards go to Rucesion, and to Huberto, to get their new armor: the Journeyman for the males, the Benusta for the females.
Other than that, it is recommended that Wizards stick to simple weapons, i.e., those that drain the least mana, until they reach their nineteenth insight, and are able to use a Staff. Coral Earrings, available from Torrance the Mileth Armorer, enhance a Wizard's Intelligence, and can be worn at the eighth insight. While some recommend rushing to the Rucesion Armorer to purchase elemental necklaces and belts as soon as they are able, I've never seen the point of doing so until your Student is more closely aligned with their element, at which point, they will probably have access to Leather or Mythril belts that also offer elemental protection.
Your Student will learn his early Secrets, namely his elemental spells, from Dar, the Dark Wizard of Mileth. This is where those Centipede's Glands and Bat's Wings you've been hoarding will come in handy, as Dar requests many bizarre things in order to learn these spells. I highly recommend providing these for your Student, at least the first one; you don't want him going down to the Crypt to bash Centipedes before he even learns his first spell.
Dar's shop is also important for another reason: it is where Wizards can Research. Xilan has written a wonderful treatise on Research and Enchantment, Artis Mystiklan, Vol. 1, which details the mechanics of Research available to even first-circle Wizards, and Enchantments that will become available to them at later insights. I am somewhat unfamiliar with the process, but after talking to several Wizards about it, I can offer some common sense advice. All Perishable items, those that are consecrated or enchanted, including Small Spinel and Emerald Rings, should be removed, and even deposited into one's bank account, before Research is attempted, as its effects can be deadly, and any Perishable items will be claimed by Sgrios should something go awry, Glioca forbid. Also, the Wizard should have some idea of what he wants to accomplish before he begins his research, and should get rid of unnecessary items before he starts. If he wishes to scribe Arcane Scrolls, for instance, he should carry only blank Parchments; if he wishes to brew Red Potions, he should carry only Viper's Glands. Finally, while there is no scientific evidence indicating one form of Research is safer than another, the general consensus among the Wizards I've spoken with is that Alchemy is the most dangerous form, followed by Enchantment; Sorcery appears to be rather benign, and Anylzation has, to all the Wizards I've discussed it with, proven harmless.
At later insights, Wizards will be able to learn valuable Lore Skills from the Rogue Trainer in Suomi, and other Skills and Spells from the Dark Wizards in Suomi and Undine. Some of their most powerful spells can be learned in hard-to-reach areas, though, like Astrid and Pravat Cave.
The best-case scenario for a Wizard is to put something between himself and his prey, and mercilessly cast spells on it until it ceases movement. Two of the more popular choices of things to put between the Wizard and his prey are Crypt walls, and other Aislings. By standing behind a wall and throwing his spells at creatures on the other side, a Wizard can ensure that his prey cannot harm him directly, although he will be vulnerable if the creature can cast spells as well. Care must also be taken to avoid hostile creatures on his side of the wall; your Student must be aware of approaching creatures, or those Sgrios-spawn that suddenly appear near him. It is much more effective to hunt with a Warrior or Monk, however, as the Wizard can stand back and cast his spells while his partners cover the front lines.
Whatever you do, do not fail to stress this strongly enough to your Wizard Students: they should never, ever Research alone. If they cannot find an Assistant, they should wait; otherwise, it is just too dangerous, and it is a danger that is easily avoided. When Researching with another, the Assistant should stand facing the Researcher, so that the Assistant can cast beothaich deur; this will lessen, but not negate, the chances of dying, a fact to which many a mage would be willing to testify. Encourage your Student to Assist others, as well; Assisting someone makes it more likely that they will be willing to Assist your Student in the future. As the Student gains insight, and begins experimenting with other forms of Enchantment, he will need Assistants of other Paths in order to complete the infusion of mystical energies into the item he is creating. And, of course, a Wizard should always be on the lookout for hunting partners, especially those that can appreciate the gifts he has to offer.