WOW:pre-Naxx mage gear

The best item pieces and gems depend upon the rest of your gear. It's therefore impossible to say exactly which gem and which item will be the best as it depends on the rest of your gear. However if you follow these rules you will be pretty close to the best you can get.

Gems
Use a Chaotic Skyflare Diamond Gem for your meta gem.
For red slots use 19 gems.
For yellow use 8 crit 9 dmg gems.
For blue use 9 dmg 12 stamina gems.

Gear
Head
Crown of Unbridled Magic - Heroic Oculus
This is the best you can get without setting foot in raids, however heroic oculus isn't a very common heroic for people to try to do so if you can't get it get this.
Flamebringer's Crown - Quest Reward
The only problem with this is that to make it good you need to use expensive gems which you might not want to spend the money on. If this is the case go for one of these.
Volkhan's Hood - Halls of Lightning
Cowl of the Vindictive Captain - Quest Reward

Enchant
Arcanum of Burning Mysteries - Kirin Tor Revered

Neck
Titanium Spellshock Necklace - Crafted
This is a very good neck piece. Its expensive though, around 1600g. It's worth it in my opinion though.

Shoulder
Dark Runic Mantle - AH
Pretty cheap from the AH so get it early in your gearing.

Enchant
Greater Inscription of the Storm - Sons of Hodir Exalted
Lesser Inscription of the Storm - Sons of Hodir Honored
Use this enchant untill you are exalted. There are dailys that give reputation so be sure to do these.

Back
Deathchill Cloak - Crafted
Costs about 800g. Only downside is it lacks stamina and intellect. Get it as it's very difficult to replace.

Enchant
Greater Speed - Enchanter

Chest
Ebonweave Robe - Crafted
The ebonweave gear has loads of hit on it. Its very nice until your other gear gets you close to 11% without it. You could also get the spellweave robe if hit is no problem.

Enchant
Powerful Stats - Enchanter

Wrists
Azure Cloth Bindings - Heroic VH

Enchant
Greater Spellpower - Enchanter

Hands
Spellweave Gloves - Crafted
There is an ebonweave version that has hit however the hit from your chest should hopefully be satisfactory make the spellweave gloves better. Bear in mind though that the spellweave sets and ebonweave are interchangeable depending on how much hit you have.

Enchant
Exceptional Spellpower - Enchanter

Waist
Plush Sash of Guzbah - Badges
Sash of the Servant - Heroic Azjol Nerub
These two are pretty close. The badge piece is better until you have very good gear though.

Enchant
Eternal Belt Buckle - Blacksmith
This is very often forgotten. It adds an extra gem slot to your waist.

Legs
Woven Bracae Leggings - Heroic HoL

Enchant
Sapphire Spellthread - Tailor

Feet
Sandals of Crimson Fury - Wyrmrest Exalted
This is the second reputation grind you should do. They are very hard to replace.

Enchant
Icewalker - Enchanter

Ring 1
Titanium Spellshock Ring - Crafted
Expensive, 1600g, get it. You pretty much won't replace it until new gear gets added.

Ring 2
Signet of the Kirin Tor - Bought
I wouldn't consider this to be worth it due to its massive price. If you are totally loaded you might want to get it though.
Annhylde's Ring - Heroic Utgarde Keep

Trinket 1
Sundial of the Exiled - 40 Badges

Trinket 2
Mark of the War Prisoner - Heroic VH
This is a very useful trinket that will help you reach the 11% hit rate when your other gear doesn't reach there. Once your gear is good enough to get there without it replace this with one of these other trinkets.
Forge Ember - Heroic HoS
Cannoneer's Fuselighter - Quest reward
This is from a pretty short quest chain so it will probably be worth getting before aiming for the better trinkets.

Weapon
Flameheart Spell Scalpel - Kirin Tor Revered
This should be your first reputation reward. Don't bother getting to exalted as there are no rewards that are really worth it.

Enchant
Mighty Spellpower - Enchanter
The price of this one will mean unless you have a lot of money lying around you will probably go for the lesser version.
Exceptional Spellpower - Enchanter

Offhand
Ward of the Violet Citadel - 25 Badges
There are only 3 better offhands in the game at the moment.