So, picasa web albums are no more. You now need to put all of your photos in Google+. That's ok, it's a nice interface integrates with posts on Google+ etc but how can you embed these albums on your cloudsite?
It's not possible in Google+ BUT all of your albums are still available on Picasa page.
If you navigate to this URL you will see all of your Google+ albums. From here you can select your albums and choose the “link to this album” option in the right hand menu. Here you will see the “Embed Slideshow” option that will provide for you an embed code. The resulting embed code can then be pasted into the HTML editor of your post or page.