acts_as_shopping_cart documentation?

Hello everyone, I'm trying to build a shopping cart for my new project and i decided to use the acts_as_shopping_cart gem, well didnt really decide to but really the only one i could find without going the spree route. Does anyone know of any good tutorials or basic doumentation other than whats found on the github page? https://github.com/crowdint/acts_as_shopping_cart & https://github.com/crowdint/acts_as_shopping_cart_app Its unclear in the sample application on how to create a new product, when I create a new product on my app it says, 2 errors, owner needs to exist and item needs to exist. Can anyone help me out with this, or have a better solution for creating a cart. This gem is quite a few years old now.