... https://picasaweb.google.com/home

I had wondered about this myself and stumbled upon the answer by accident. I chose to upload a photo via Picassa Photo Viewer, right click & chose "Quick Upload" , this opens up the webpage detailed above whereupon I can re-organise my Album Ïnstant Upload, chose action/delete to remove individual photos.

Curious though, that there there is no way to do this via G+

Slm :)