When setting up your domain to use Google Apps email services you will be prompted to verify the ownership of your domain. When logged into your Google Apps account at this step select Alternate Methods > Add a DNS Record to Your Domains Configuration. Select the registrar as Name.com and a unique verification string will be generated. Copy this entire string and complete the following steps:
Log into your Name.com account.
Click the domain you have configured Google Apps for and click DNS Record Management.
Select TXT from the drop down menu and paste the unique string into the Record Answer field, click Add Record.
Once this is done you can choose Verify on the Google Apps setup page.