Create new contacts for your Gmail account.
Enter your contact's information in the appropriate fields.
Any information you add will save automatically.
If you notice that email addresses are added to your contacts, even though you didn't add them:
Gmail automatically adds addresses to your Contacts list each time you use the Reply, Reply to all, or Forward functions to send mail to addresses that don't already exist in your Contacts list. Each time you mark a message as 'Not Spam,' your Contacts list is also automatically updated so that future messages from that sender are received in your inbox. If these addresses don't appear immediately, try waiting a few minutes or signing out of your account and signing back in.