Most ecommerce or shopping cart platforms out there have native GA ecom tracking integration that can be turned on at the flip of a switch. Before doing anything, check the documentation for the ecom technologies you are using or contact your rep to find out if the integration already exists. If there is no native integration, then follow Google's documentation as others have mentioned.

Some problems arrises while tracking in Google Analytics for ecommerce website in NY. Recently i have read an article about this. It was an informative article and have a precise information about the problems faced while tracking in google analytics. Some basic problems are listed below: Inaccurate Traffic Data The Missing Transaction Issue Problem with PAYPAL Incorrectly using the unit price Ecommerce just like any other website also needs correct data. But, is Google Analytic service beneficial for Ecommerce site? The answer is still confusing, but according to a professional Ecommerce website development in USA, the solutions needs to be found in order to get accurate results.