What kind of credentials do I need to teach at in the graphic and web design field?

[Angrygirl5]

I have a bachelor's degree from 1997 in design. I have also been taking occasional classes since then in order to update my skills. I have work experience working in print production and also I currently work in an art department. I really want to do something different and several people have told me that I should consider teaching. How do I teach at the college level? Do I need a master's degree to even apply? I was considering art schools. Is there a way I could just be an adjunct teacher to see if I even like teaching? I really do not want to teach at the high school level because I have no patience for children and do not like how they are so spoiled nowindays.