Open Gmail and sign in to your account
Click the Google Apps icon in the top-right corner
Select Contacts
In Google Contacts, click Create label on the left side
Enter a name for the group
Click Save
Select the contacts you want to add to the group
Click the Labels icon
Choose the group label you created
Click Apply
To email the group, open Gmail and click Compose
In the To field, type the group label name
Select the label from the suggestions
Send your email