Rails community produced several ecommerce projects worth checking. Railcast is known video tutorial site provides a list of video tutorials for each ecommerce project developed in Rails

Railcast eCommerce - good set of videos to follow in order to implement ecommerce application in Ruby on Rails

eCommerce on Rails - sample project developed by open source community

There are good AngularJS tutorials for eCommerce applications that can be used for Rails.

AngularJS ecommerce - simple application developed over several parts developed with Bootstrap CSS framework

AngularJS Mobile eCommerce with Bootstrap - codeproject ecommerce application

If you want to build ecommerce shop with Rails there are several online tutorials that help you to do just that

Shopping Cart from Rich on Rails - simple tutorial that covers eCommerce models as well as controllers required to get you started.

You can also look at full featured Opensource project on github.

Spree Commerce - full featured open source ecommerce store