Q: how do i add photos to my photo streams from my mac?

Hi ada,

Drag the photos you want to add to a photo stream from the photos, events, or albums folder to the Photo Stream folder under Web in the sidebar. Once you see the green + sign, lift your finger off of the mouse or trackpad, and a window with your photo stream folders will come up (including an option to create a photo stream). Click on the one you want the photos published to and a window will come up asking if you want to publish the photos to the photo stream you have selected. It will also provide you with the ability to put in a comment if you wish. Click on Publish, and the photos will be added.

Cheers,

GB

What version of iPhoto are you using?

You might find this helpful: http://help.apple.com/iphoto/mac/9.4/#phtac7ec5f4.  There's a section on photo stream under "Share photos digitally".