Where to find cute business/work clothes?

I'm 22 and will begin my first year of teaching in August and I need to build my "teacher" wardrobe. I've looked at Macys, Belk, New York $ Co, H & M and basically any other name brand place you can think of. I will wear dresses, skirts, and dress pants with nice tops but I don't want to look like I am 40. So, where can I get some "fun" work clothes for a decent price?