How to Turn ON My Photo Stream in iPhoto?

You need to set up your iCloud account on your computer and then turn ON My Photo Stream. You need an Apple ID to login to iCloud. Any new photos that you import into iPhoto are uploaded to iCloud and added to My Photo Stream. So you need to turn ON 'My Photo Stream' on computer and each iOS device to upload photos to iCloud. When you turn ON 'My Photo Stream' and added photos in your photo stream, then they are automatically imported into your iPhoto Library. To turn ON 'My Photo Stream' in iPhoto, open iPhoto and select 'Photo Stream' located at the 'Source List'. Click Turn ON 'Photo Stream'. You can change your settings for adding photos to your photo stream or for importing photos into your iPhoto library. To change settings, open 'iPhoto' and click 'Preferences' and then click 'Photo Stream'.