Im sure thats what they are called, to be more specific they are the magic symbols that you put on the ground and they expload with Fire,shock or frost.. What im asking is is there a npc that sells the spell? thank you

Try the court mages in the larger cities or in Winterhold

College of Winterhold is your best bet.

Faralda at the College, Farengar Secret-Fire at Dragonsreach (Whiterun) and Sybille Stentor at the Blue Palace (Solitude) should sell the spell tomes. They also appear as random loot every now and then.