Four levels of teaching generally exist in nursing: the associate level, bachelor's, master's and doctorate. Associate degrees are typically offered at community colleges and offer entry-level positions in the nursing field. Bachelor's, master's and doctoral programs offer more lucrative opportunities the further up you progress. A bachelor's is typically a prerequisite for a master's while a master's is a prerequisite for a doctorate.
Typically teaching nursing requires that teachers have at least a master's degree (MSN, or Master of Science), particularly at the bachelor's and associate levels. Teaching a level usually requires that you have a degree one level higher than the level you're teaching; therefore teaching at a master's level requires that you have a doctorate. The degrees available are Associate Degree in Nursing (ADN), Bachelor of Science in Nursing (BSN) and Master of Science in Nursing (MSN).
"Practical Nursing" is an entry-level course offered at several community colleges and is an introduction to associate or bachelor's-level courses. Though state requirements vary, typical requirements include a minimum of two years' experience as a registered nurse, which can be accomplished through an associate degree.
Just having a master's or doctorate will qualify you to teach college-level nursing. Most educational facilities will also require you to be an RN (registered nurse) and have several years of nursing experience. You should refer to state guidelines before attempting to apply to teach nursing.