Your new question is fairly dependent on a lot of factors, but you want to start you build by looking at a combination of Ray of Frost (either Snow Blast or Cold Blood). Snow Blast is technically our highest DPS, but it takes time for it to ramp up. If you are doing hit and run, then Cold Blood will serve you better and leave you more mana to work with.
Magic Missile with Charged Blast is going to be your best single target Primary unless you are trying to trigger a proc of some sort. If you are, then Electrocute is were you want to look for that. A good primary is important to keeping the damage up while you regen mana.
For raw damage increase, Force Weapon is an obvious buff worth taking. Sparkflint will increase both your attacks and provide shots of its own.
Hydra is probably the best spell for adding additional single target damage for little mana. The other Force and Conjuration spells are geared more towards AoE. Conflagration will cause the Hydra to give you an additional 10% boost to your damage.
Slow time can be used to boost damage in several ways in addition to providing some defense. Stretch time will provide a nice 10% increase to attack speed.
Arcane Dynamo, Conflagration, and Glass Cannon are going to be the passives you want to look at first.
So to sum it up, assuming single target with no worries about survival here is a good start:
Ray of Frost (Snow Blast or Cold Blood),
Magic Missile (Charged Blast),
Magic Weapon (Force Weapon),
Familiar (Sparkflint),
Slow Time (Stretch Time),
Hydra,
Arcane Dynamo,
Conflagration,
Glass Cannon
Always check out armor to see if it's better than the armor you currently have. Look for items that increase your stats, especially intelligence (Wizard's primary attribute.) Also, Wizards can use wands and staffs and various other weapons, so look for those as well.
Eventually you will probably want to start picking up only magic (blue) and rare (yellow) items as these sell for much more gold (tens or hundreds instead of 2 or 3) than regular weapons. Also, these can be salvaged by the blacksmith to get crafting supplies which can be used to craft better weapons in time.
Best Answer
If you consider uncontrolled spells as well, then runed Arcane Torrent with Arcane Dynamo gives 11x the base damage: see the first answer in What abilities will consume the Arcane Dynamo stacks? and its linked spreadsheet.