Managing and getting in touch with contacts is as easy ever with Google contacts. Here's a collection of resources to help you learn how.
Enter Addresses and Add Contacts
Auto-complete email addresses, use the contact picker, and add personal contacts.
Create Groups and Mailing Lists
Create contact groups to organize your personal contacts and to use as personal mailing lists.
Contacts vs. Google Groups
Contacts are a way to store and organize information about the people you communicate with and Google Groups support such things as a discussion group. View the recap on the difference between Google Contacts and Groups.
For even more information about using Google Contacts, check out the Gmail Help Center.