I have a lot of valuable data which I want to be stored in my Google Apps because I will be leaving a job. So I want to know how to backup data including e-mails, contacts, calendar, documents, etc.
Is there any easy method?
Google has some pretty easy to use services regarding this type of problem. You can use your Google Mail account to download all your mails to your personal computer using a mail client such as Microsoft Outlook. Also you can use Google Mail to export your Contacts list in a CSV or vCard format and also you can download your Google Calendar entries. For your documents and files you can use Google Drive that helps you to store and download anywhere, anytime files only by using your Google account. For some other kind of data or files you can check the Google support page.