Google Analytics is a very powerful tool to help business owners measure the performance of their web site. It takes time to get to know how the data is organised and each business may have different ideas on what they want to measure.
Simply add your Google Analytics ID into Netbookings Settings and you then be able see how people get to your Netbookings, how they behave while there and you can also use the E-commerce information for conversion tracking and overall revenue.
You can setup goals and make changes to your web site to help achieve those goals. For example you may want to offer a free trial of your booking software (Netbookings). Setup a goal that starts with the click on the Free button and then end goal is the screen being displayed after the form is completed and submitted.