How much and how long?

It usually takes between 1-2 years to finish up the prereqs, depending on how many years ago your graduated from high school and what your SAT/ACT scores were. High enough scores will get you out of certain math classes. I believe you can avoid taking Chemistry if you've taken it within the last five years. There are certain English and Computer classes you may be able to test out of as well.

In general, the prereqs you will most likely need to take are: Algebra, English (possibly a couple), Speech, I had to take an Interpersonal Relationships class that dealt with culture and ethics, Biology (which is a prereq to Chemistry that you may not need to take depending on when you graduated high school), Nutrition, Human Growth and Development, Anatomy and Physiology (usually takes two semesters to complete), Statistics (some ADN programs do not require this, but you will need to take it when you move along to your BSN), Microbiology, Psychology. I *think* that's everything. Everything I can think of anyway.

The actual nursing prereqs are the science-related ones and they're usually weighed more heavily when being considered for admission into the nursing program (though not always).

I had 22 credits. It took me two years to complete working full time.

64 credits here (associate's degree), took me 18 months, 16-20 credits per semester, plus full summers.