At 300, you can begin to learn new formulas from Three Grand Master Enchanter Trainers found in Outland (Burning Crusade Expansion)

In Shattrath (undeniably the hub of Outland and the location where you will choose between two factions, Aldor & Scryer) High Enchanter Bardolan (43,92) is a Scryer. So choosing Scryer will allow you to continue visiting Bardolan in Shattrath.

For those favoring Aldor, you'll need to take an inconvenient trip to Honor Hold and find Grand Master Enchanter Johan Barnes at 53,66 (Hellfire Peninsula). He's located 1 level below the top of the tower. Or find Asarnan in Netherstorm at 43,33 (Southern area of the large Northern-most island).
Both appear to be neutral.

However, until you make the faction choice between Aldor & Scryer.. anyone can freely visit Bardolan in Shattrath.