Follow the instructions below to create a data service using a sample Google spread sheet as the data source.
1. Log on to the Data Services Server Management Console.
2. Click the Main tab and select the Create link under Data Services.
3. The Create Data Service page appears. Fill in the fields and click Next. The Data Service name is mandatory.
Info:
For more information on Advanced Configurations in creating data services, refer to the Transaction Handling section.
4. The Data Sources page appears. Click on the Add New Data Source link and add your Data Source details. Select the data source type as Google Spread Sheet.
You can use either private or public Google spread sheets as the data source. If the spread sheet is Private, you will be prompted to enter the user name and the password. For example,
Click Save. You have added a Data Source to your Web Service. Click Next to proceed.
6. The Queries page appears.
Initially your service does not include any queries. Click on 'Add New Query' to add a new query, input/output mappings, events etc. to your Data Service. Enter query details according to the structure of the response you want.
Click the Add New Output Mapping button to define how the output looks like. In this example, we create Customer Number as element and Customer Name and City as attributes as follows:
Click on Main Configuration once you enter the output mappings and Save the query details.
You have added one query to your data service configuration. Click Save.
7. After saving, the added data source page appears. You can edit or delete the Data Source. To proceed click "Next."
8. The Operations page appears. Click the Add new operation link to create an operation. Select a query to be executed when this operation is called. For example,
Click Save once done.
9. The operation will be listed in the operations page. 
The Data Service configuration is done. Click Finish. (You can continue to add resources by clicking the Next button if you like)
10. You will be navigated to the "Deployed services" page.
From here, you can manage your service.