How often Do I take out my Nipple piercing?

I just got my pierced today as a spur of the moment type of thing ( I doo these things alot). Anyways, since I never really planned on getting this done, I have no idea on how to take care of it. I know I have to put salt water on it, clean it and what not, but my real question is.... Do I take it our every night and put it back in every morning? Do I have to take it out to clean it? and how would I go about changing it to a different ornament?