Worldweavers series by Alma Alexander. "For readers suffering withdrawal (from) Harry Potter, this new series might just suffice." - VOYA
In that series, by order they're in:
1. "Gift of the Unmage" - Meet a cast of mages, tricksters, brooding elves with the souls of Ferengi... and Thea Winthrop and a bunch of misfit kids from The Last Ditch School for the Incurably Incompetent.
2. "Spellspam" - What if spam suddenly started carrying magic spells? What if something promising you a clear complexion gave you transparent skin? Thea Winthrop and her friends are pitted against a dangerous mage who can destroy their world.
3. "Cybermage" - When Thea Winthrop and her friends find a way to break into a cube created by the wizard of the west, Nikola Tesla, they uncover a secret which will change their world forever.