Get my photos on all my devices
You want to enable photo stream, and really every kind of sharing there is.  I personally don't use iCloud for photo sync, but instead I use DropBox with Carousel.  The reason for this is that Carousel has a much simpler interface, and automatically takes care of all syncing (provided you use the Carousel app for viewing photos).  You also can have more space to store (1TB or more depending on your plan, as much as 50GB for the free plan, depending on what you've done in it - I have 8GB)