1. Select the photos you would like to share from your iPhoto Library.
2. Click on File -> Export
3. Click on Picasa and make sure you have Better Quality selected.
4. Sign in to Picasa with your Google Apps account.
5. Click Allow access.
6. Fill in any more details (e.g. album name etc) and click Export.
7. Click on view to go to Picasa & see your album
8. Make sure your album is Public on the Web. Click on Link to this Album.
9. Click on Embed Slideshow
10. Select Large and copy the embed code in the box at the bottom.
11. Switch over to your blog and open the post you want to put the slideshow in. Create a post title, write your text, and don't forget to add some labels (Keywords).
To add the slideshow, click on the HTML button (top left).
12. Go to the end of the text, then Paste the embed code you copied earlier.
13. Click on Compose again, and you should see your slideshow embedded in your blog post. You can continue and publish from there.