Open it, and copy everything into a folder on your computer, and you are done with the basic backup. This is something you should do once every few months.
For more regular backups, you have a variety of options. You can use an app – of which there are several – and quite a few of them are free. You can take a piecemeal approach and backup individual items separately. To back up your mail, contact lists, calendar entries and settings, you can use Google as the back up source.
Go to Settings and then Privacy. Make sure the check boxes for ‘Back up my settings’ and ‘Automatic Restore’ are selected. From there, go back and select ‘Account & Sync’ and select the boxes ‘Sync Contacts’, ‘Sync Gmail’, ‘Sync Calendar’.
For photographs, you have a variety of options. You can use the Google Plus app. After logging into your Google Plus account, enable Instant Upload through the Settings menu. Make sure that the Sync box for instant upload is selected in your Accounts and Sync settings is selected.
Alternatively, just manually drag and drop the contents of the DCIM folder into your PC, after connecting it with your USB cable.