I see everyone using these circle boost cards on themselves at my level.  Did I miss a card vendor somewhere?

Look for spells available to you from wiki at Wizard101central.com http://www.wizard101central.com/wiki/. Once on site, choose "Spells" then your school from the menu on left. The spell you should be looking for has name ending with blade (eg. Life Blade, Storm Blade).

There are also other spells to increase your spells power: Trap from your own school (eg. Life Trap), Feint from Death School if you are going Death, you can buy boost spells from balance school at balance tree in Krokotopia, there are several items giving boost cards, some schools have spell giving bonus to all cast spells of that school (eg. Balefrost), and Sun School has some spell boosts.

Ah yes, our new Star School Auras! These were released in October of 2010.

Star School (Auras) 

The star school is focused around a new type of magic called Auras. Auras are magical energy that surround and protect or strengthen the Wizard. Auras are unique and different from other magic in that they can't be stacked, broken, or dispelled but they will disappear over time. Auras can boost accuracy, damage, resistance, or even convert incoming spells to pips for you. 

Auras are cast as normal spells and can only have a target of "Self". Auras have a timer on them that is counted in rounds. After this timer is complete the aura is removed. Auras cannot be stacked with other Auras and Casting a subsequent Aura spell will replace the previous one. 

Effects of Auras
Auras have a few different special effect types that will be specific to them such as Stun Resistance, Pip Conversion, Accuracy Boost, Resistance Boost and Damage Boost. 

  Specific Auras & their Color
Aura of Fortification ( Blue ) - This grants the player 15% resistance to all attacks.
Aura of Amplification ( Red ) - The grants the player a 15% bonus to outgoing damage.
Aura of Precision ( Green ) - This grants the player a 10% bonus to accuracy.
Aura of Conviction ( Yellow ) - This grants the player 90% resistance to stuns and 20% block chance.
Aura of Empowerment ( Purple ) - This grants the player an extra pip every time a rank 4 or higher spell is used on him / her.
Aura of Vengeance ( Orange ) - This grants the player a 20% boost to their critical hit chance. 

These spells can be purchased with Training Points in Celestia.

Hope that helps! For more information, please visit our Game Updates page for October 2011 at https://www.wizard101.com/game/community/updatenotes/october2010 and 

https://www.wizard101.com/game/community/updatenotes for the most recent updates.