I am a newbie to this forum. I am hoping that I can get help for my Ipad....My wife and I share an Ipad. We both like to read. We have separate Amazon accts. How do I use the kindle app for both accounts?

I don't think it is possible. You could try switching your registration back and forth in the Kindle app, but my instincts tell me that's a recipe for disaster; or at least some painful cleanup when things get confused.

Amazon has a lending feature that may work for some of the books you want to share.